[{"id":"white-clover--cabbage--living_mulch","plant_a":"white-clover","plant_b":"cabbage","direction":"a_to_b","status":"supported","effect_type":"living_mulch","polarity":"benefit","target_pest_or_disease":["cabbage root fly","cabbage aphid","cabbage white caterpillars"],"claim":"Undersowing cabbage with white clover reduced egg-laying and infestation by several cabbage pests in replicated field trials, and a 2023 meta-analysis of cabbage intercropping found substantially lower pest injury on average.","mechanism":"Ground cover of non-host plants disrupts pest host-finding (\"inappropriate landings\"): insects that land on clover leave the area more often than they find cabbage.","outcome_measures":["pest egg counts","larval infestation","pest injury"],"evidence_tier":"A","evidence_type":"meta_analysis","source_ids":["finch-collier-2000","theunissen-1995","carrillo-reche-2023"],"study_context":"Field trials in the UK and Netherlands; white cabbage undersown with clover; meta-analysis of cabbage intercropping trials.","production_context":"field","spatial_arrangement":"undersown","distance_or_density":"Continuous clover cover under and between cabbage plants.","relative_planting_time":"Sow clover 2–4 weeks after transplanting cabbage, or mow established clover before transplanting.","overlap_requirement":"Clover must cover the ground while cabbage is vulnerable (transplant to heading).","management_requirements":["Mow or trim clover to 5 cm when it reaches 15 cm","Sow clover later than cabbage or keep it in strips to limit competition"],"applicability_notes":"Applies to home beds where the ground between cabbages can be fully covered; a few clover plants at one end will not reproduce the effect.","limitations":"The same trials and the meta-analysis found a modest reduction in cabbage head size or yield from competition. The benefit is lower pest injury, not higher yield.","contradicting_record_ids":["white-clover--cabbage--root_competition"],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"white-clover--cabbage--root_competition","plant_a":"white-clover","plant_b":"cabbage","direction":"a_to_b","status":"avoid","effect_type":"root_competition","polarity":"harm","target_pest_or_disease":[],"claim":"Unmanaged clover competes with cabbage for water and nutrients and reduced head size in field trials; the 2023 meta-analysis found a modest average productivity reduction.","mechanism":"Competition for water, nitrogen and light at the soil surface.","outcome_measures":["head weight","marketable yield"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["theunissen-1995","carrillo-reche-2023"],"study_context":"Netherlands field trials; global meta-analysis.","production_context":"field","spatial_arrangement":"undersown","distance_or_density":"Full ground cover.","relative_planting_time":"Worst when clover is established before the cabbage.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Mow clover regularly","Delay clover sowing until cabbage is established","Irrigate in dry spells"],"applicability_notes":"A manageable trade-off, not a reason to avoid the pairing: accept a smaller head in exchange for lower pest pressure, or manage the clover.","limitations":"Yield cost varies with clover management, soil moisture and fertility.","contradicting_record_ids":["white-clover--cabbage--living_mulch"],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"white-clover--broccoli--living_mulch","plant_a":"white-clover","plant_b":"broccoli","direction":"a_to_b","status":"conditional","effect_type":"living_mulch","polarity":"benefit","target_pest_or_disease":["cabbage root fly","cabbage aphid","cabbage white caterpillars"],"claim":"The cabbage–clover pest-disruption effect is expected to transfer to broccoli (the same species, Brassica oleracea) when the ground is fully covered, but the trials were on head cabbage.","mechanism":"Disruption of pest host-finding by non-host ground cover.","outcome_measures":["pest infestation"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["finch-collier-2000","theunissen-1995","carrillo-reche-2023"],"study_context":"Cabbage trials; broccoli is a related crop of the same species.","production_context":"field","spatial_arrangement":"undersown","distance_or_density":"Continuous ground cover.","relative_planting_time":"Sow clover after broccoli is established.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Mow clover to limit competition"],"applicability_notes":"Same conditions as for cabbage.","limitations":"Not directly tested on broccoli; competition reduces head size as in cabbage.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sweet-alyssum--broccoli--insectary_support","plant_a":"sweet-alyssum","plant_b":"broccoli","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["cabbage aphid"],"claim":"Sweet alyssum strips in organic broccoli supported hoverflies whose larvae eat aphids; field agronomy showed the benefit depends on the share of the bed given to alyssum and its distance from the crop.","mechanism":"Alyssum flowers supply nectar and pollen to adult hoverflies (syrphids), which lay eggs near aphid colonies; larvae consume aphids.","outcome_measures":["hoverfly egg density","aphid density"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["brennan-2016","hogg-2011"],"study_context":"Organic broccoli fields, Salinas Valley, California; alyssum in strips or interplanted at 1–10% of the bed.","production_context":"field","spatial_arrangement":"strip","distance_or_density":"Alyssum within a few metres of the broccoli; a few plants per bed are enough.","relative_planting_time":"Transplant alyssum at the same time as broccoli so it flowers before aphids build up.","overlap_requirement":"Alyssum must be flowering while aphids are colonising the broccoli.","management_requirements":["Keep alyssum to a small share of the bed (about 5% or less)","Shear alyssum to rebloom"],"applicability_notes":"Hoverflies must be present in the area; in a small garden, the benefit is plausible but not guaranteed.","limitations":"Alyssum is a brassica and can host flea beetles. More alyssum means more competition, not more benefit.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sweet-alyssum--lettuce--insectary_support","plant_a":"sweet-alyssum","plant_b":"lettuce","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["lettuce aphid","aphids"],"claim":"Alyssum strips interplanted with organic lettuce supported hoverflies for aphid biocontrol; the agronomy showed one alyssum plant for roughly every 20–40 lettuce plants, within a few metres, was sufficient.","mechanism":"Nectar and pollen for adult hoverflies; larvae eat aphids.","outcome_measures":["hoverfly activity","aphid counts","lettuce yield"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["brennan-2013","hogg-2011"],"study_context":"Organic romaine lettuce, Salinas Valley, California.","production_context":"field","spatial_arrangement":"strip","distance_or_density":"Alyssum plants every few metres within the lettuce bed.","relative_planting_time":"Transplant together.","overlap_requirement":"Alyssum flowering during lettuce growth.","management_requirements":["Replace lettuce plants with alyssum at a ratio of roughly 1:20 to 1:40"],"applicability_notes":"Reasonable to try in a home bed of lettuce; requires local hoverflies.","limitations":"Alyssum occupies lettuce space; the trade-off was small at low ratios.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sweet-alyssum--kale--insectary_support","plant_a":"sweet-alyssum","plant_b":"kale","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["cabbage aphid"],"claim":"By extension from broccoli and lettuce trials, alyssum near kale may support hoverflies that eat cabbage aphids; not tested on kale.","mechanism":"Insectary flowers feeding aphid predators.","outcome_measures":["aphid density"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["brennan-2016","hogg-2011"],"study_context":"Related crop trials (broccoli, lettuce).","production_context":"home_garden","spatial_arrangement":"strip","distance_or_density":"Within a few metres.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Small share of the bed in alyssum"],"applicability_notes":"Plausible; indirect evidence.","limitations":"Indirect evidence only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sweet-alyssum--strawberry--insectary_support","plant_a":"sweet-alyssum","plant_b":"strawberry","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["aphids"],"claim":"Alyssum attracts hoverflies whose larvae eat aphids; an effect on strawberry aphids is plausible but untested.","mechanism":"Insectary flowers for aphid predators.","outcome_measures":["aphid density"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["hogg-2011","brennan-2016"],"study_context":"","production_context":"home_garden","spatial_arrangement":"strip","distance_or_density":"Within a few metres.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Indirect evidence from other crops.","limitations":"No strawberry-specific trial found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"marigold--tomato--pest_suppression","plant_a":"marigold","plant_b":"tomato","direction":"a_to_b","status":"conditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["glasshouse whitefly"],"claim":"French marigolds interplanted with tomatoes reduced glasshouse whitefly numbers in a UK glasshouse study; the effect was attributed to airborne limonene from the marigolds.","mechanism":"Volatile limonene released by marigold foliage repels or deters whitefly on nearby tomatoes.","outcome_measures":["whitefly adult counts"],"evidence_tier":"C","evidence_type":"greenhouse","source_ids":["conboy-2019"],"study_context":"Glasshouse compartments with tomato and French marigold (Tagetes patula) interplanted; limonene dispensers tested separately.","production_context":"protected","spatial_arrangement":"mixed","distance_or_density":"Marigolds interplanted among tomatoes at close spacing.","relative_planting_time":"Marigolds established before whitefly arrive; present throughout.","overlap_requirement":"Marigolds must be growing (not just flowering) while tomatoes are at risk.","management_requirements":["Enough marigold foliage per tomato for volatiles to accumulate","Works best in enclosed spaces"],"applicability_notes":"Most applicable in a greenhouse, polytunnel or sheltered corner; outdoors, volatiles disperse and the effect is uncertain.","limitations":"Glasshouse evidence only; no outdoor home-garden trial; no effect shown on other tomato pests.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"marigold--tomato--pest_suppression-2","plant_a":"marigold","plant_b":"tomato","direction":"a_to_b","status":"conditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["root-knot nematodes"],"claim":"Marigolds (Tagetes) suppress some root-knot nematodes, but mainly when grown as a dense cover crop for a season before tomatoes, not as a few plants beside them.","mechanism":"Alpha-terthienyl and related compounds in Tagetes roots are toxic to certain nematode species; suppression requires the roots to occupy the soil volume.","outcome_measures":["nematode population in soil","root galling in the following crop"],"evidence_tier":"B","evidence_type":"extension_synthesis","source_ids":["hooks-2010"],"study_context":"Review of marigold cover-crop and intercrop trials, mainly USA.","production_context":"field","spatial_arrangement":"relay","distance_or_density":"Dense stand (about 15–20 cm spacing) across the whole bed.","relative_planting_time":"Marigolds grown for 2–3 months in the season before the tomato crop.","overlap_requirement":"Does not require the two plants to grow together; this is a rotation practice.","management_requirements":["Choose tested cultivars (T. patula, T. erecta)","Keep the stand weed-free","Incorporate residues before planting tomatoes"],"applicability_notes":"Only where root-knot nematodes are an identified problem (mainly warm climates and sandy soils).","limitations":"Interplanted marigolds have a much smaller effect; some nematode species are unaffected or even increase.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"marigold--carrot--pest_suppression","plant_a":"marigold","plant_b":"carrot","direction":"a_to_b","status":"conditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["root-knot nematodes"],"claim":"A dense marigold cover crop in the season before carrots can reduce root-knot nematodes that fork and gall carrot roots; a few marigolds beside carrots will not.","mechanism":"Nematicidal root compounds from a full stand of Tagetes.","outcome_measures":["nematode counts","root galling"],"evidence_tier":"B","evidence_type":"extension_synthesis","source_ids":["hooks-2010"],"study_context":"Review of Tagetes cover-crop trials.","production_context":"field","spatial_arrangement":"relay","distance_or_density":"Whole-bed dense stand.","relative_planting_time":"Season before carrots.","overlap_requirement":"Not required; rotation practice.","management_requirements":["Full stand for 2–3 months","Incorporate before sowing carrots"],"applicability_notes":"Where nematodes are confirmed.","limitations":"Species-specific; not a cure for carrot fly or other problems.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"basil--tomato--spatial_complement","plant_a":"basil","plant_b":"tomato","direction":"mutual","status":"conditional","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"In replicated field trials, tomato–basil mixtures used land more efficiently than either crop alone at some planting densities (land equivalent ratio above 1), without any special interaction beyond ordinary competition.","mechanism":"Basil occupies the lower canopy and root zone beside taller, deeper-rooted tomatoes, so the two share space with limited competition when density is moderate.","outcome_measures":["land equivalent ratio","tomato yield","basil yield"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["bomford-2009"],"study_context":"West Virginia, USA; biointensive beds; several densities of tomato and basil mixtures.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"Basil 30–45 cm from tomato stems; avoid crowding basil under the tomato canopy.","relative_planting_time":"Transplant together after frost.","overlap_requirement":"Both are warm-season crops and overlap naturally.","management_requirements":["Prune lower tomato leaves so basil gets light","Do not increase total density beyond what each crop would have alone"],"applicability_notes":"A practical pairing because season, sun and watering needs match. The benefit is efficient use of space, not pest control or flavour.","limitations":"At high densities basil was shaded and yields fell; the study did not measure pest effects.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"basil--tomato--flavor_or_growth","plant_a":"basil","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"flavor_or_growth","polarity":"benefit","target_pest_or_disease":[],"claim":"Gardeners widely report that basil improves tomato flavour or growth. The reviewed field study measured yields and land-use efficiency, not flavour, and found no growth effect beyond ordinary competition.","mechanism":"None demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["bomford-2009","umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Treat as tradition; grow the two together for convenience, not for flavour.","limitations":"No controlled flavour evaluation found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"basil--tomato--pest_suppression","plant_a":"basil","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["aphids","whitefly","tomato hornworm"],"claim":"Basil is commonly said to repel aphids, whitefly and hornworms from tomatoes. The review found no field trial establishing this for basil; the volatile-repellent evidence in tomatoes is for French marigold in a glasshouse.","mechanism":"Proposed: aromatic volatiles; not demonstrated for basil in the field.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment only.","limitations":"No controlled trial found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"brussels-sprouts--tomato--root_competition","plant_a":"brussels-sprouts","plant_b":"tomato","direction":"mutual","status":"conflicting","effect_type":"root_competition","polarity":"neutral","target_pest_or_disease":[],"claim":"Popular charts say tomatoes and Brussels sprouts (and other brassicas) should not be grown together. In the same field trials that tested basil, tomato–Brussels sprout mixtures behaved like any other mixture: no harmful interaction, just competition that depended on density.","mechanism":"No inhibitory mechanism demonstrated; both are large plants that compete for light, water and nutrients at close spacing.","outcome_measures":["land equivalent ratio","yields"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["bomford-2009","umn-companion"],"study_context":"West Virginia, USA; replicated field plots.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Neither reward nor penalty; plan by space, light and water like any two large crops. Note they belong to different rotation groups with different soil-disease risks.","limitations":"One study, one site; the tradition remains widespread.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"corn--pole-beans--physical_support","plant_a":"corn","plant_b":"pole-beans","direction":"a_to_b","status":"supported","effect_type":"physical_support","polarity":"benefit","target_pest_or_disease":[],"claim":"Corn stalks provide physical support for climbing beans; in measured Three Sisters plots the polyculture produced more food energy and protein per area than the same crops grown separately.","mechanism":"Beans climb the corn stalk, replacing a trellis; the crops differ in height and rooting and share space efficiently.","outcome_measures":["yield per area","energy and protein per area"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["mt-pleasant-2016","umn-companion"],"study_context":"Field plots in New York State comparing the Three Sisters with monocultures.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"Beans sown at the base of corn plants, 2–3 beans per stalk, in blocks.","relative_planting_time":"Sow beans 2–3 weeks after corn, when corn is about 30 cm tall.","overlap_requirement":"Corn must be established before beans climb it.","management_requirements":["Use a sturdy, tall corn cultivar","Limit beans per stalk so they do not pull corn down","Plant corn in blocks for pollination"],"applicability_notes":"Works in a home bed large enough for a corn block (at least 1.2 × 1.2 m).","limitations":"Individual crop yields were lower than monocultures; the gain is per area, not per plant. Sweet corn is weaker-stalked than the flour corns used historically.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"pole-beans--corn--nutrient_transfer","plant_a":"pole-beans","plant_b":"corn","direction":"a_to_b","status":"conditional","effect_type":"nutrient_transfer","polarity":"benefit","target_pest_or_disease":[],"claim":"Beans fix nitrogen, but reviews show only a small, variable share reaches neighbouring corn during the season; most benefit comes after bean residues decompose, that is, to the following crop.","mechanism":"Rhizobial nitrogen fixation; transfer to neighbours through root exudates and decomposition.","outcome_measures":["nitrogen transfer","corn nitrogen status"],"evidence_tier":"B","evidence_type":"meta_analysis","source_ids":["thilakarathna-2016","mt-pleasant-2016"],"study_context":"Review of legume nitrogen-transfer studies; Three Sisters plots.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"","relative_planting_time":"Benefit accrues mainly to the crop planted after the beans.","overlap_requirement":"In-season benefit is small; do not rely on it.","management_requirements":["Leave bean roots and residues in the bed"],"applicability_notes":"Plan corn fertility as if the beans were not there; treat extra nitrogen as a bonus for next season.","limitations":"Transfer during the season is typically under 10–15% of fixed nitrogen.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"winter-squash--corn--spatial_complement","plant_a":"winter-squash","plant_b":"corn","direction":"mutual","status":"supported","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Squash vines spread beneath corn and beans, shading the soil and suppressing weeds, while corn grows above; the measured Three Sisters polyculture out-yielded the separate crops per area.","mechanism":"Complementary canopies: tall corn, ground-level squash; squash leaves reduce weed growth and soil evaporation.","outcome_measures":["yield per area","weed cover"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["mt-pleasant-2016"],"study_context":"Field plots, New York State.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"Squash hills between corn blocks, 1–1.5 m apart.","relative_planting_time":"Sow squash 1–2 weeks after corn.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Give squash room at the edge of the corn block","Expect harvest access to be awkward"],"applicability_notes":"Suits gardens with a corn block and space for vines to run.","limitations":"Harvesting corn among squash vines is awkward; squash yields per plant are lower than in the open.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"pole-beans--winter-squash--spatial_complement","plant_a":"pole-beans","plant_b":"winter-squash","direction":"mutual","status":"conditional","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Climbing beans and sprawling squash occupy different layers; measured as part of the three-crop system, not as a pair.","mechanism":"Vertical versus ground-level growth.","outcome_measures":["yield per area"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["mt-pleasant-2016"],"study_context":"Three Sisters plots.","production_context":"field","spatial_arrangement":"mixed","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Only as part of the corn–bean–squash arrangement; beans need a support.","limitations":"Not tested as a two-crop pair.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"collards--cabbage--trap_crop","plant_a":"collards","plant_b":"cabbage","direction":"a_to_b","status":"conditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["diamondback moth"],"claim":"Collards planted around cabbage attracted diamondback moth egg-laying and reduced the need to spray the cabbage in Florida field trials, provided the collard trap rows were maintained and treated.","mechanism":"Diamondback moths prefer to lay eggs on collards; larvae concentrate there instead of on cabbage.","outcome_measures":["egg and larval counts on cabbage","insecticide applications"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["mitchell-2000","sare-trap-crops","shelton-2006"],"study_context":"Florida, USA; collard rows around cabbage plots.","production_context":"field","spatial_arrangement":"perimeter","distance_or_density":"A continuous border row of collards around the cabbage block.","relative_planting_time":"Plant collards 1–2 weeks before cabbage so they are larger and more attractive.","overlap_requirement":"Collards must be present and attractive throughout the cabbage crop.","management_requirements":["Check the collards weekly","Remove or treat larvae on the trap rows before they move to the cabbage"],"applicability_notes":"Only where diamondback moth is a known problem; a single collard plant will not protect a bed.","limitations":"An unmanaged trap crop becomes a nursery for the pest.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"mustard-greens--cabbage--trap_crop","plant_a":"mustard-greens","plant_b":"cabbage","direction":"a_to_b","status":"conditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["flea beetles","cabbage white caterpillars","harlequin bug"],"claim":"Mustard is used on farms as a perimeter trap crop for several brassica pests because it is more attractive than cabbage; the practice depends on early planting and destroying pests in the trap rows.","mechanism":"Pest preference for mustard over cabbage.","outcome_measures":["pest counts on main crop"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["sare-trap-crops","shelton-2006"],"study_context":"Farm-scale guidance and trap-crop reviews.","production_context":"field","spatial_arrangement":"perimeter","distance_or_density":"Border rows.","relative_planting_time":"Sow mustard 1–2 weeks before the cabbage.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Monitor and treat or remove infested mustard"],"applicability_notes":"Large beds with a clear perimeter.","limitations":"In a small garden, mustard more often simply hosts the same pests.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"winter-squash--cucumber--trap_crop","plant_a":"winter-squash","plant_b":"cucumber","direction":"a_to_b","status":"conditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["striped cucumber beetle"],"claim":"A perimeter of Blue Hubbard squash intercepted striped cucumber beetles arriving at butternut squash fields and reduced insecticide use; the same approach is plausible for cucumbers but was tested on squash.","mechanism":"Cucumber beetles strongly prefer Blue Hubbard; planting it at the perimeter, earlier than the main crop, concentrates beetles where they can be managed.","outcome_measures":["beetle counts on main crop","insecticide applications"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["cavanagh-2009","sare-trap-crops"],"study_context":"On-farm trials in Massachusetts and Connecticut; butternut squash main crop.","production_context":"field","spatial_arrangement":"perimeter","distance_or_density":"Trap plants at the edge the beetles arrive from, about 1–2 m from the crop.","relative_planting_time":"Transplant Blue Hubbard 1–2 weeks before the cucumbers.","overlap_requirement":"Trap crop must be larger and more attractive than the cucumbers at beetle arrival.","management_requirements":["Treat or remove beetles on the trap plants","Use the Blue Hubbard cultivar specifically"],"applicability_notes":"Most useful where cucumber beetles and bacterial wilt are recurring problems.","limitations":"Extrapolated from squash to cucumber; requires management the study relied on.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"winter-squash--zucchini--trap_crop","plant_a":"winter-squash","plant_b":"zucchini","direction":"a_to_b","status":"conditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["striped cucumber beetle"],"claim":"Blue Hubbard squash at the perimeter can draw cucumber beetles away from summer squash, as shown for butternut squash fields, if planted earlier and managed.","mechanism":"Pest preference for Blue Hubbard.","outcome_measures":["beetle counts"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["cavanagh-2009","sare-trap-crops"],"study_context":"Butternut squash trials.","production_context":"field","spatial_arrangement":"perimeter","distance_or_density":"1–2 m from the crop at the arrival edge.","relative_planting_time":"1–2 weeks before the zucchini.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Manage beetles on trap plants"],"applicability_notes":"Where beetles recur.","limitations":"Extrapolated from a related crop.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"onion--carrot--pest_suppression","plant_a":"onion","plant_b":"carrot","direction":"a_to_b","status":"conditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["carrot rust fly"],"claim":"In UK field trials, carrot fly damage fell only when onions greatly outnumbered carrots (about four onion rows per carrot row) and only until the onions began to bulb; at garden-typical ratios the effect was small or absent.","mechanism":"Onion volatiles are thought to mask carrot odour used by the fly to find hosts; the effect needs a high density of actively growing onion foliage.","outcome_measures":["carrot fly larval damage"],"evidence_tier":"B","evidence_type":"field_trial","source_ids":["uvah-coaker-1984","umn-companion"],"study_context":"Field trials with carrot–onion mixtures at several ratios.","production_context":"field","spatial_arrangement":"row","distance_or_density":"About 4:1 onion to carrot rows, interleaved.","relative_planting_time":"Sow together; protection ends when onions bulb.","overlap_requirement":"Onions must be in leafy growth during carrot fly egg-laying periods.","management_requirements":["Maintain the high onion ratio","Use a mesh barrier as the reliable control"],"applicability_notes":"Rarely practical in a home bed; treat it as a minor supplement to mesh covers.","limitations":"Weak at equal ratios; no protection after onion bulbing, which often coincides with the second carrot fly generation.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"dill--cabbage--insectary_support","plant_a":"dill","plant_b":"cabbage","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["cabbage aphid","cabbage white caterpillars"],"claim":"Flowering dill is attractive to hoverflies, lacewings and parasitic wasps that attack cabbage pests; an effect on pest numbers in cabbage is plausible but not directly measured.","mechanism":"Small, open umbel flowers supply nectar and pollen to natural enemies.","outcome_measures":["beneficial insect visits"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["hogg-2011","letourneau-2011"],"study_context":"Field observation of insect visits to insectary plants (California); diversity meta-analysis.","production_context":"field","spatial_arrangement":"strip","distance_or_density":"Within a few metres of the cabbage.","relative_planting_time":"Sow dill 2–3 weeks before cabbage so it flowers during the pest season.","overlap_requirement":"Dill must be flowering while cabbage pests are present; leafy dill does nothing for beneficials.","management_requirements":["Let dill flower","Stagger sowings for continuous bloom"],"applicability_notes":"Low-cost experiment with a documented mechanism.","limitations":"No cabbage-specific outcome trial found; dill is tall and self-seeds.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cilantro--cabbage--insectary_support","plant_a":"cilantro","plant_b":"cabbage","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["cabbage aphid"],"claim":"Flowering coriander was among the plants most visited by hoverflies and parasitic wasps in field observations; benefit to cabbage depends on flowering during the pest season.","mechanism":"Insectary flowers for natural enemies.","outcome_measures":["beneficial insect visits"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["hogg-2011"],"study_context":"California field observations.","production_context":"field","spatial_arrangement":"strip","distance_or_density":"Within a few metres.","relative_planting_time":"Sow 3–4 weeks before cabbage; let it bolt.","overlap_requirement":"Flowering must coincide with pest presence.","management_requirements":["Allow bolting","Succession sow"],"applicability_notes":"Easy experiment.","limitations":"No cabbage-specific trial.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"buckwheat--cabbage--insectary_support","plant_a":"buckwheat","plant_b":"cabbage","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["cabbage aphid","cabbage white caterpillars"],"claim":"Buckwheat flowers are strongly attractive to hoverflies and parasitic wasps; a strip beside cabbage may support natural enemies if it flowers during the pest season.","mechanism":"Nectar for natural enemies.","outcome_measures":["beneficial visits"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["hogg-2011","letourneau-2011"],"study_context":"Insectary plant field observations.","production_context":"field","spatial_arrangement":"strip","distance_or_density":"Adjacent strip.","relative_planting_time":"Sow 4–5 weeks before the pest season.","overlap_requirement":"Flowering buckwheat during the pest period.","management_requirements":["Cut before seed set","Resow every 3 weeks"],"applicability_notes":"Simple strip experiment.","limitations":"General evidence; no cabbage-specific outcome.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"buckwheat--cucumber--insectary_support","plant_a":"buckwheat","plant_b":"cucumber","direction":"a_to_b","status":"conditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":["aphids"],"claim":"Buckwheat supports hoverflies and parasitic wasps that may reduce aphids on cucumbers; plausible, untested on cucumber.","mechanism":"Insectary flowers.","outcome_measures":["beneficial visits"],"evidence_tier":"C","evidence_type":"field_trial","source_ids":["hogg-2011"],"study_context":"","production_context":"home_garden","spatial_arrangement":"strip","distance_or_density":"Adjacent strip.","relative_planting_time":"Sow 4–5 weeks before cucumbers flower.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Cut before seed"],"applicability_notes":"Experiment.","limitations":"Indirect.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--lettuce--shade_or_shelter","plant_a":"tomato","plant_b":"lettuce","direction":"a_to_b","status":"conditional","effect_type":"shade_or_shelter","polarity":"benefit","target_pest_or_disease":[],"claim":"Lettuce bolts and scorches in summer heat; the partial shade cast by tomatoes on their east or north side can extend the lettuce season. This is a spatial fit, not a biological companion effect.","mechanism":"Shade lowers leaf temperature and slows bolting in a heat-sensitive crop.","outcome_measures":["bolting","leaf quality"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["cornell-growing-guides","brooker-2015"],"study_context":"Extension guidance on summer lettuce and general intercropping synthesis.","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Lettuce 30–45 cm from tomato stems on the shaded side.","relative_planting_time":"Sow or plant lettuce after tomatoes are 60 cm tall, in early summer.","overlap_requirement":"Only meaningful in hot weather; in spring lettuce needs full sun.","management_requirements":["Keep lettuce watered; tomato roots compete for water"],"applicability_notes":"Summer only, in climates where lettuce struggles with heat.","limitations":"Too much shade produces weak lettuce; in cool climates it is a disadvantage.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"corn--lettuce--shade_or_shelter","plant_a":"corn","plant_b":"lettuce","direction":"a_to_b","status":"conditional","effect_type":"shade_or_shelter","polarity":"benefit","target_pest_or_disease":[],"claim":"Corn casts deep shade to its north (in the northern hemisphere), which can keep summer lettuce cooler; in cool climates the same shade is a disadvantage.","mechanism":"Shade reduces heat stress and bolting.","outcome_measures":["bolting"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["cornell-growing-guides","brooker-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Lettuce along the shaded side of the corn block.","relative_planting_time":"Plant lettuce once corn is knee-high.","overlap_requirement":"Summer heat period.","management_requirements":["Extra water; corn is a heavy drinker"],"applicability_notes":"Hot summers.","limitations":"Not a benefit in cool or cloudy climates.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"radish--carrot--temporal_complement","plant_a":"radish","plant_b":"carrot","direction":"a_to_b","status":"conditional","effect_type":"temporal_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Radishes sown in the same row as slow-germinating carrots mark the row, break the soil crust and are harvested before the carrots need the space; a relay in time rather than a biological interaction.","mechanism":"Different maturity dates let two crops use the same row in sequence.","outcome_measures":["space use","row marking"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["cornell-growing-guides","rhs-grow-your-own","brooker-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"relay","distance_or_density":"Mixed in the same row at low radish density.","relative_planting_time":"Sow together; pull radishes at 3–4 weeks.","overlap_requirement":"Short overlap only; remove radishes promptly.","management_requirements":["Pull radishes before they crowd carrot seedlings"],"applicability_notes":"Any carrot sowing.","limitations":"Radishes left too long compete with carrot seedlings; both are hosts for different root pests.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"carrot--lettuce--spatial_complement","plant_a":"carrot","plant_b":"lettuce","direction":"mutual","status":"conditional","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Deep-rooted carrots and shallow-rooted lettuce use different soil layers and similar light, so they interplant with little competition at normal spacing; a space-use principle from intercropping research rather than a crop-specific trial.","mechanism":"Complementary root depth and canopy size.","outcome_measures":["land equivalent ratio (general)"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["brooker-2015","cornell-growing-guides"],"study_context":"","production_context":"home_garden","spatial_arrangement":"row","distance_or_density":"Alternate rows 30 cm apart.","relative_planting_time":"Sow together in spring.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Useful for filling a bed; both are cool-season crops.","limitations":"General principle; no carrot–lettuce trial found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"peas--lettuce--shade_or_shelter","plant_a":"peas","plant_b":"lettuce","direction":"a_to_b","status":"conditional","effect_type":"shade_or_shelter","polarity":"benefit","target_pest_or_disease":[],"claim":"Tall peas on netting cast light shade that can shelter late-spring lettuce as days warm; after the peas finish, the lettuce space is free for a summer crop.","mechanism":"Light shade and sequence of occupancy.","outcome_measures":["bolting","space use"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["cornell-growing-guides","brooker-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"row","distance_or_density":"Lettuce on the shaded side of the pea row, 30 cm away.","relative_planting_time":"Plant lettuce 3–4 weeks after peas.","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Spring beds.","limitations":"General practice; untested as a pair.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"potato--tomato--disease_risk","plant_a":"potato","plant_b":"tomato","direction":"mutual","status":"avoid","effect_type":"disease_risk","polarity":"harm","target_pest_or_disease":["late blight (Phytophthora infestans)"],"claim":"Potato and tomato are both hosts of late blight; spores spread readily between adjacent plants, and infected potato foliage or volunteers are a common source of tomato infection. Extension services advise keeping them apart and rotating the nightshade group.","mechanism":"Shared pathogen with airborne spores; one crop acts as an inoculum source for the other.","outcome_measures":["late blight incidence"],"evidence_tier":"B","evidence_type":"extension_synthesis","source_ids":["umn-diseases","uc-ipm-home","umn-companion"],"study_context":"Extension and IPM guidance based on pathogen biology.","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Separate beds; as far apart as the garden allows.","relative_planting_time":"Planted together","overlap_requirement":"Risk whenever both crops have foliage during wet, mild weather.","management_requirements":["Remove volunteer potatoes","Use resistant cultivars","Destroy infected foliage promptly"],"applicability_notes":"Serious in humid or wet-summer regions; a hard constraint in the planner wherever late blight occurs.","limitations":"In dry climates with no late blight history the risk is lower; they still share Colorado potato beetle and early blight.","contradicting_record_ids":[],"hard_constraint":true,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"corn--tomato--shared_pest","plant_a":"corn","plant_b":"tomato","direction":"mutual","status":"avoid","effect_type":"shared_pest","polarity":"harm","target_pest_or_disease":["corn earworm / tomato fruitworm (Helicoverpa zea)"],"claim":"Corn earworm and tomato fruitworm are the same moth. Moths emerging from corn move readily to adjacent tomatoes, so extension guidance advises separating the two crops.","mechanism":"Shared pest moving between hosts; corn silks and tomato fruit are both egg-laying sites.","outcome_measures":["fruitworm damage"],"evidence_tier":"B","evidence_type":"extension_synthesis","source_ids":["uc-ipm-home","umn-companion"],"study_context":"Pest biology from IPM programmes.","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Different beds or opposite ends of the garden.","relative_planting_time":"Planted together","overlap_requirement":"Risk from corn silking until tomato harvest ends.","management_requirements":["Monitor tomatoes for entry holes when corn is silking"],"applicability_notes":"A weighted warning, not a block: the moth flies well, so separation reduces but does not remove the risk.","limitations":"Where earworm is rare (cool maritime climates) the concern is minor.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"potato--eggplant--shared_pest","plant_a":"potato","plant_b":"eggplant","direction":"mutual","status":"avoid","effect_type":"shared_pest","polarity":"harm","target_pest_or_disease":["Colorado potato beetle","Verticillium wilt"],"claim":"Eggplant is a preferred host of Colorado potato beetle and shares soil-borne wilts with potato; adjacent plantings let beetles move between them.","mechanism":"Shared pest and pathogens within the nightshade family.","outcome_measures":["beetle damage"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["uc-ipm-home","umn-diseases"],"study_context":"","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Separate beds.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Hand-pick beetles","Rotate nightshades together"],"applicability_notes":"Where Colorado potato beetle occurs (North America, Europe).","limitations":"Manageable trade-off; mainly a rotation issue.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--strawberry--disease_risk","plant_a":"tomato","plant_b":"strawberry","direction":"mutual","status":"avoid","effect_type":"disease_risk","polarity":"harm","target_pest_or_disease":["Verticillium wilt"],"claim":"Strawberries and tomatoes share Verticillium wilt, a soil-borne fungus. The main risk is planting strawberries where nightshades recently grew; adjacency in the same season adds a smaller risk through shared soil.","mechanism":"Soil-borne pathogen common to both hosts.","outcome_measures":["wilt incidence"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["umn-diseases","rhs-grow-your-own"],"study_context":"","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Different beds; do not plant strawberries after tomatoes for 3 years.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Choose resistant strawberry cultivars","Keep bed history"],"applicability_notes":"Mostly a rotation and bed-history concern.","limitations":"Manageable; many gardens never see Verticillium.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"potato--strawberry--disease_risk","plant_a":"potato","plant_b":"strawberry","direction":"mutual","status":"avoid","effect_type":"disease_risk","polarity":"harm","target_pest_or_disease":["Verticillium wilt"],"claim":"Potatoes and strawberries share Verticillium wilt; avoid planting strawberries in beds that grew potatoes in the last three years.","mechanism":"Soil-borne pathogen.","outcome_measures":["wilt incidence"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["umn-diseases","rhs-grow-your-own"],"study_context":"","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Separate beds.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Keep bed history","Resistant cultivars"],"applicability_notes":"Rotation concern.","limitations":"Manageable.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--raspberry--disease_risk","plant_a":"tomato","plant_b":"raspberry","direction":"mutual","status":"avoid","effect_type":"disease_risk","polarity":"harm","target_pest_or_disease":["Verticillium wilt"],"claim":"Raspberries share Verticillium wilt with nightshades; do not establish a raspberry row where tomatoes or potatoes grew recently.","mechanism":"Soil-borne pathogen.","outcome_measures":["wilt incidence"],"evidence_tier":"C","evidence_type":"extension_synthesis","source_ids":["umn-diseases"],"study_context":"","production_context":"home_garden","spatial_arrangement":"adjacent","distance_or_density":"Separate area.","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":["Keep bed history"],"applicability_notes":"Bed-history concern for a permanent crop.","limitations":"Manageable.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"nasturtium--cabbage--trap_crop","plant_a":"nasturtium","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars","aphids"],"claim":"Nasturtiums are said to draw cabbage white butterflies and aphids away from brassicas. They are certainly colonised by both pests; the review found no controlled trial showing that nearby cabbage benefits.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion","shelton-2006"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Unmanaged, a nasturtium covered in caterpillars or aphids is a nursery, not a trap. Trap cropping needs the pests on the trap plant to be removed.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"nasturtium--bush-beans--trap_crop","plant_a":"nasturtium","plant_b":"bush-beans","direction":"a_to_b","status":"traditional","effect_type":"trap_crop","polarity":"benefit","target_pest_or_disease":["black bean aphid"],"claim":"Nasturtiums are said to lure black bean aphids away from beans. Nasturtiums are a favoured aphid host, but no study shows reduced aphids on adjacent beans.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Aphids multiply on the nasturtium and can spread to beans unless removed.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"nasturtium--cucumber--pest_suppression","plant_a":"nasturtium","plant_b":"cucumber","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cucumber beetles","squash bugs"],"claim":"Nasturtiums are said to deter cucumber beetles and squash bugs. No controlled evidence was found; the documented cucumber-beetle strategy is a Blue Hubbard squash trap crop.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"marigold--cabbage--pest_suppression","plant_a":"marigold","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars","cabbage root fly"],"claim":"Marigolds are widely claimed to repel cabbage pests. The marigold evidence concerns glasshouse whitefly on tomatoes (limonene) and soil nematodes (cover crop); neither transfers to cabbage caterpillars or root fly.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion","conboy-2019"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"No brassica-specific evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"marigold--bush-beans--pest_suppression","plant_a":"marigold","plant_b":"bush-beans","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["Mexican bean beetle"],"claim":"Marigolds are said to deter Mexican bean beetle. No controlled evidence found.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"borage--tomato--pest_suppression","plant_a":"borage","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["tomato hornworm"],"claim":"Borage is said to deter tomato hornworm and improve tomato growth. No controlled evidence found. Borage flowers do attract bees, which tomatoes do not need for fruit set.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Borage is large and deep-rooted; at close spacing it competes with tomatoes.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"borage--strawberry--flavor_or_growth","plant_a":"borage","plant_b":"strawberry","direction":"a_to_b","status":"traditional","effect_type":"flavor_or_growth","polarity":"benefit","target_pest_or_disease":[],"claim":"Borage is said to improve strawberry flavour and yield and to attract pollinators. Bee visits are real; the flavour and yield claim has no controlled evidence.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Borage shades low strawberry plants if planted too close.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"borage--zucchini--pollination","plant_a":"borage","plant_b":"zucchini","direction":"a_to_b","status":"traditional","effect_type":"pollination","polarity":"benefit","target_pest_or_disease":[],"claim":"Borage flowers are heavily visited by bumblebees and honeybees, which squash need for fruit set; whether borage measurably improves squash pollination in a garden has not been tested.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Plausible mechanism; no outcome study found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"basil--pepper--pest_suppression","plant_a":"basil","plant_b":"pepper","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["aphids"],"claim":"Basil is said to repel aphids and improve peppers, by extension from the tomato tradition. No pepper-specific evidence; basil and peppers do share season and watering needs, which makes them convenient neighbours.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Convenience pairing, not evidence.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"chives--carrot--pest_suppression","plant_a":"chives","plant_b":"carrot","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["carrot rust fly"],"claim":"Chives and other alliums are said to deter carrot rust fly. The only field evidence is for onions at very high ratios; chives have not been tested.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion","uvah-coaker-1984"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Mesh is the reliable control.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"chives--strawberry--pest_suppression","plant_a":"chives","plant_b":"strawberry","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["aphids"],"claim":"Chives are said to deter aphids and improve strawberry health. No controlled evidence found.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"garlic--tomato--pest_suppression","plant_a":"garlic","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["aphids","spider mites"],"claim":"Garlic is said to repel aphids and spider mites from tomatoes. No controlled evidence for interplanted garlic found. Garlic is in the bed from autumn to early summer, so overlap with tomatoes is short.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Timing overlap is limited; garlic is lifted as tomatoes establish.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sage--cabbage--pest_suppression","plant_a":"sage","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars"],"claim":"Sage is said to deter cabbage moths and carrot fly. No controlled evidence found. Sage also needs far drier soil than cabbage.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Water needs conflict.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"mint--cabbage--pest_suppression","plant_a":"mint","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars","aphids"],"claim":"Mint is said to repel cabbage pests, ants and aphids. No controlled evidence found, and mint spreads aggressively into vegetable beds.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Grow mint in a container regardless.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"thyme--cabbage--pest_suppression","plant_a":"thyme","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars"],"claim":"Thyme is said to deter cabbage white butterflies. No controlled evidence found; thyme prefers much drier soil.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Water needs conflict.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"rosemary--carrot--pest_suppression","plant_a":"rosemary","plant_b":"carrot","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["carrot rust fly"],"claim":"Rosemary is said to deter carrot rust fly. No controlled evidence found. Rosemary needs dry, lean soil unlike carrots.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Water and soil conflict.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"rosemary--bush-beans--pest_suppression","plant_a":"rosemary","plant_b":"bush-beans","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["Mexican bean beetle"],"claim":"Rosemary is said to repel bean beetles. No controlled evidence found.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"radish--cucumber--pest_suppression","plant_a":"radish","plant_b":"cucumber","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cucumber beetles"],"claim":"Radishes are said to deter cucumber beetles. No controlled evidence found.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"bush-beans--potato--pest_suppression","plant_a":"bush-beans","plant_b":"potato","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["Colorado potato beetle","Mexican bean beetle"],"claim":"Beans are said to deter Colorado potato beetle, and potatoes to deter Mexican bean beetle. No controlled evidence was found for either direction.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"carrot--tomato--flavor_or_growth","plant_a":"carrot","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"flavor_or_growth","polarity":"benefit","target_pest_or_disease":[],"claim":"A popular book title aside, no study shows that carrots improve tomatoes or vice versa. Carrots do fit beneath tomatoes spatially but are shaded and compete for water as tomatoes grow.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Spatial fit is marginal once tomatoes are large.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--asparagus--pest_suppression","plant_a":"tomato","plant_b":"asparagus","direction":"mutual","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["asparagus beetle"],"claim":"Tomatoes are said to deter asparagus beetle and asparagus to deter nematodes in tomatoes. No controlled evidence found; asparagus ferns shade summer tomatoes.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Asparagus is permanent and shading.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"spinach--strawberry--spatial_complement","plant_a":"spinach","plant_b":"strawberry","direction":"mutual","status":"traditional","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Spinach and strawberries are said to grow well together. They are both low and cool-season, so they coexist without conflict, but no benefit has been shown.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Neutral fit, not a benefit.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"beet--onion--spatial_complement","plant_a":"beet","plant_b":"onion","direction":"mutual","status":"traditional","effect_type":"spatial_complement","polarity":"benefit","target_pest_or_disease":[],"claim":"Beets and onions are commonly listed as good neighbours. They have compatible needs and sizes; no benefit beyond ordinary compatibility has been demonstrated.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Compatible, not beneficial.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cucumber--sunflower--physical_support","plant_a":"cucumber","plant_b":"sunflower","direction":"a_to_b","status":"traditional","effect_type":"physical_support","polarity":"benefit","target_pest_or_disease":[],"claim":"Sunflowers are sometimes used as living trellises for cucumbers. Mechanically plausible, but sunflowers shade heavily, compete for water and are not tested as supports.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Use a trellis.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"peas--spinach--shade_or_shelter","plant_a":"peas","plant_b":"spinach","direction":"a_to_b","status":"traditional","effect_type":"shade_or_shelter","polarity":"benefit","target_pest_or_disease":[],"claim":"Peas are said to shelter spinach. Light shade from peas can delay spinach bolting; this is a spatial fit rather than evidence.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Untested.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"rhubarb--cabbage--pest_suppression","plant_a":"rhubarb","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars"],"claim":"Rhubarb is said to deter brassica pests, sometimes by using its leaves as a spray. No controlled evidence; rhubarb leaf sprays are not recommended.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Rhubarb shades neighbours heavily.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"calendula--tomato--pest_suppression","plant_a":"calendula","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["tomato hornworm","aphids"],"claim":"Calendula is said to deter tomato hornworm and aphids. No controlled evidence; calendula itself hosts aphids, and its open flowers do feed hoverflies.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition; insectary value is general.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"lavender--cabbage--pest_suppression","plant_a":"lavender","plant_b":"cabbage","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cabbage white caterpillars"],"claim":"Lavender is said to repel cabbage moths. No controlled evidence; lavender needs dry, lean soil that cabbage would not tolerate.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Soil and water conflict.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"oregano--cucumber--pest_suppression","plant_a":"oregano","plant_b":"cucumber","direction":"a_to_b","status":"traditional","effect_type":"pest_suppression","polarity":"benefit","target_pest_or_disease":["cucumber beetles"],"claim":"Oregano is said to repel cucumber beetles. No controlled evidence found.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"Tradition only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cosmos--tomato--insectary_support","plant_a":"cosmos","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"insectary_support","polarity":"benefit","target_pest_or_disease":[],"claim":"Cosmos is said to attract beneficial insects that protect tomatoes. Cosmos flowers do feed hoverflies and bees, but no tomato outcome has been measured.","mechanism":"Proposed by tradition; not demonstrated in a controlled comparison.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"Optional experiment, not a guarantee.","limitations":"General insectary value only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"fennel--tomato--allelopathy","plant_a":"fennel","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"allelopathy","polarity":"harm","target_pest_or_disease":[],"claim":"Fennel is widely listed as inhibiting tomatoes and most other vegetables. Laboratory bioassays find inhibitory compounds in fennel, but no field study shows an effect at garden spacing; fennel is tall, deep-rooted and a strong competitor, which explains most observations.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["duke-2015","umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Allelopathy not demonstrated in the field; competition is real.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"fennel--bush-beans--allelopathy","plant_a":"fennel","plant_b":"bush-beans","direction":"a_to_b","status":"traditional","effect_type":"allelopathy","polarity":"harm","target_pest_or_disease":[],"claim":"Fennel is said to stunt beans. Only laboratory evidence of inhibitory compounds exists; field effects are unproven.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["duke-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Competition for light and water is the practical issue.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sunflower--potato--allelopathy","plant_a":"sunflower","plant_b":"potato","direction":"a_to_b","status":"traditional","effect_type":"allelopathy","polarity":"harm","target_pest_or_disease":[],"claim":"Sunflowers are said to inhibit potatoes and beans through allelopathy. Laboratory bioassays show inhibitory compounds in sunflower residues, but a field effect on neighbours at normal spacing is not established; shade and water competition explain most reports.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["duke-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Lab evidence only.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sunflower--pole-beans--allelopathy","plant_a":"sunflower","plant_b":"pole-beans","direction":"a_to_b","status":"traditional","effect_type":"allelopathy","polarity":"harm","target_pest_or_disease":[],"claim":"Sunflowers are said to stunt beans. Laboratory evidence only; shading is the demonstrable problem.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["duke-2015"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Shade and competition, not chemistry.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"onion--bush-beans--flavor_or_growth","plant_a":"onion","plant_b":"bush-beans","direction":"mutual","status":"traditional","effect_type":"flavor_or_growth","polarity":"harm","target_pest_or_disease":[],"claim":"Alliums and beans are traditionally listed as enemies, sometimes with the claim that onions inhibit bean growth. No controlled evidence was found in either direction.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"No mechanism identified.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"garlic--peas--flavor_or_growth","plant_a":"garlic","plant_b":"peas","direction":"mutual","status":"traditional","effect_type":"flavor_or_growth","polarity":"harm","target_pest_or_disease":[],"claim":"Garlic and peas are traditionally listed as incompatible. No evidence found; garlic is lifted in early summer as peas finish, so they rarely overlap for long anyway.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Minimal overlap in time.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--cabbage--root_competition","plant_a":"tomato","plant_b":"cabbage","direction":"mutual","status":"traditional","effect_type":"root_competition","polarity":"harm","target_pest_or_disease":[],"claim":"Tomatoes and cabbage-family crops are traditionally kept apart. The one field test of this tradition (tomato with Brussels sprouts) found ordinary competition and no harmful interaction.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["bomford-2009","umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"See the conflicting-evidence record for Brussels sprouts.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"dill--tomato--flavor_or_growth","plant_a":"dill","plant_b":"tomato","direction":"a_to_b","status":"traditional","effect_type":"flavor_or_growth","polarity":"harm","target_pest_or_disease":[],"claim":"Mature, flowering dill is said to stunt tomatoes while young dill helps them. No controlled evidence for either; dill is tall and self-seeds, which can crowd neighbours.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"Manage dill's size and seeding.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cucumber--potato--disease_risk","plant_a":"cucumber","plant_b":"potato","direction":"mutual","status":"traditional","effect_type":"disease_risk","polarity":"harm","target_pest_or_disease":[],"claim":"Cucumbers and potatoes are traditionally kept apart, sometimes citing blight. Late blight of potato (Phytophthora infestans) does not infect cucumbers; no shared disease justifies the rule.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-diseases"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"No mechanism; the planner treats this as no verified relationship for risk purposes.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"pole-beans--onion--flavor_or_growth","plant_a":"pole-beans","plant_b":"onion","direction":"mutual","status":"traditional","effect_type":"flavor_or_growth","polarity":"harm","target_pest_or_disease":[],"claim":"Climbing beans and onions are traditionally listed as incompatible. No controlled evidence found.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"No mechanism identified.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"kohlrabi--tomato--flavor_or_growth","plant_a":"kohlrabi","plant_b":"tomato","direction":"mutual","status":"traditional","effect_type":"flavor_or_growth","polarity":"harm","target_pest_or_disease":[],"claim":"Kohlrabi and tomatoes are traditionally said to stunt each other. No evidence found for either direction.","mechanism":"Claimed by tradition; no harmful interaction demonstrated.","outcome_measures":[],"evidence_tier":"D","evidence_type":"tradition","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner does not separate these plants on this claim; it evaluates space, light, water and timing normally.","limitations":"No mechanism identified.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--cucumber--other","plant_a":"tomato","plant_b":"cucumber","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between tomato and cucumber.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Both are warm-season, thirsty crops; the practical question is light competition from tomatoes and space for cucumber vines, which the planner checks from plant attributes.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--pepper--other","plant_a":"tomato","plant_b":"pepper","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between tomato and pepper.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Same family: no live companion effect is documented, but they share wilts and flea beetles and must rotate together. See the rotation section.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"pepper--eggplant--other","plant_a":"pepper","plant_b":"eggplant","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between pepper and eggplant.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Same family and rotation group; no companion effect documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"pepper--marigold--other","plant_a":"pepper","plant_b":"marigold","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between pepper and marigold.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"The glasshouse whitefly study was on tomato; no pepper trial found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"tomato--zucchini--other","plant_a":"tomato","plant_b":"zucchini","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between tomato and zucchini.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Both large, thirsty, warm-season plants; space and airflow matter, not a companion effect.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cucumber--bush-beans--other","plant_a":"cucumber","plant_b":"bush-beans","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between cucumber and bush beans.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Commonly listed as good companions; no evidence found either way.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"peas--carrot--other","plant_a":"peas","plant_b":"carrot","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between peas and carrot.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Often listed together; no evidence of benefit or harm.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"lettuce--strawberry--other","plant_a":"lettuce","plant_b":"strawberry","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between lettuce and strawberry.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Both low and shallow-rooted; they compete for water but no relationship is documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"onion--lettuce--other","plant_a":"onion","plant_b":"lettuce","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between onion and lettuce.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Commonly listed as compatible; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"carrot--onion--other","plant_a":"carrot","plant_b":"onion","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between carrot and onion.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"The documented effect runs from onion to carrot (carrot fly, conditional). Whether carrots reduce onion fly has no usable evidence.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"potato--corn--other","plant_a":"potato","plant_b":"corn","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between potato and corn.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented; both are heavy feeders.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cucumber--melon--other","plant_a":"cucumber","plant_b":"melon","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between cucumber and melon.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Cucumbers (Cucumis sativus) and melons (Cucumis melo) are different species and do not cross-pollinate, so the common worry about flavour is unfounded. No other relationship is documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"zucchini--pumpkin--other","plant_a":"zucchini","plant_b":"pumpkin","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between zucchini and pumpkin.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Both Cucurbita pepo cultivars can cross-pollinate, but that only affects seed saved for next year, never this season's fruit. No other relationship is documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"garlic--strawberry--other","plant_a":"garlic","plant_b":"strawberry","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between garlic and strawberry.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Garlic interplanted with strawberries is sometimes recommended; no usable evidence was found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"spinach--peas--other","plant_a":"spinach","plant_b":"peas","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between spinach and peas.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Commonly listed together; no evidence of an effect.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"kale--onion--other","plant_a":"kale","plant_b":"onion","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between kale and onion.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"beet--bush-beans--other","plant_a":"beet","plant_b":"bush-beans","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between beet and bush beans.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Tradition says beets and pole beans conflict but bush beans are fine; no evidence for either claim.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"swiss-chard--tomato--other","plant_a":"swiss-chard","plant_b":"tomato","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between swiss chard and tomato.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"broccoli--tomato--other","plant_a":"broccoli","plant_b":"tomato","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between broccoli and tomato.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"See the Brussels sprout record for the only field test of the brassica–tomato tradition; broccoli itself is untested.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"sweet-potato--bush-beans--other","plant_a":"sweet-potato","plant_b":"bush-beans","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between sweet potato and bush beans.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"okra--pepper--other","plant_a":"okra","plant_b":"pepper","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between okra and pepper.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Sometimes recommended for shade; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"celery--cabbage--other","plant_a":"celery","plant_b":"cabbage","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between celery and cabbage.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"parsley--tomato--other","plant_a":"parsley","plant_b":"tomato","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between parsley and tomato.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"leek--carrot--other","plant_a":"leek","plant_b":"carrot","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between leek and carrot.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"The onion–carrot fly evidence was for bulb onions at high density; leeks were not tested.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"blueberry--strawberry--other","plant_a":"blueberry","plant_b":"strawberry","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between blueberry and strawberry.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Different soil pH needs; no companion relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"asparagus--parsley--other","plant_a":"asparagus","plant_b":"parsley","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between asparagus and parsley.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"lettuce--radish--other","plant_a":"lettuce","plant_b":"radish","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between lettuce and radish.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Commonly interplanted for space; no benefit or harm documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"bok-choy--cilantro--other","plant_a":"bok-choy","plant_b":"cilantro","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between bok choy and cilantro.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented; both cool-season.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"turnip--peas--other","plant_a":"turnip","plant_b":"peas","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between turnip and peas.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"raspberry--garlic--other","plant_a":"raspberry","plant_b":"garlic","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between raspberry and garlic.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Sometimes recommended; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"rhubarb--strawberry--other","plant_a":"rhubarb","plant_b":"strawberry","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between rhubarb and strawberry.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Often grown together; no relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"arugula--bush-beans--other","plant_a":"arugula","plant_b":"bush-beans","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between arugula and bush beans.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"mustard-greens--onion--other","plant_a":"mustard-greens","plant_b":"onion","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between mustard greens and onion.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"collards--onion--other","plant_a":"collards","plant_b":"onion","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between collards and onion.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"cauliflower--celery--other","plant_a":"cauliflower","plant_b":"celery","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between cauliflower and celery.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"eggplant--bush-beans--other","plant_a":"eggplant","plant_b":"bush-beans","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between eggplant and bush beans.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"winter-squash--nasturtium--other","plant_a":"winter-squash","plant_b":"nasturtium","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between winter squash and nasturtium.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired against squash bugs; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"melon--corn--other","plant_a":"melon","plant_b":"corn","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between melon and corn.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Sometimes grown together for shade; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"parsnip--onion--other","plant_a":"parsnip","plant_b":"onion","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between parsnip and onion.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"No relationship documented.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1},{"id":"kohlrabi--beet--other","plant_a":"kohlrabi","plant_b":"beet","direction":"mutual","status":"unknown","effect_type":"other","polarity":"neutral","target_pest_or_disease":[],"claim":"We did not find a source that establishes a benefit or harm between kohlrabi and beet.","mechanism":"None documented.","outcome_measures":[],"evidence_tier":"unknown","evidence_type":"none","source_ids":["umn-companion"],"study_context":"","production_context":"home_garden","spatial_arrangement":"unspecified","distance_or_density":"","relative_planting_time":"Planted together","overlap_requirement":"Both plants must be present at the same time.","management_requirements":[],"applicability_notes":"The planner evaluates spacing, light, water and timing normally.","limitations":"Traditionally paired; no evidence found.","contradicting_record_ids":[],"hard_constraint":false,"reviewer":"Garden Planner editorial team (pending independent horticultural review)","reviewed_at":"2026-08-15","version":1}]