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Entire healthy mature carrot plant in a real garden bed, showing growth habit and scale.Primary identification image. 25–40 cm tall, 10–15 cm wide at maturity.

Carrot

Daucus carota subsp. sativus (Hoffm.) Schübl. & G. Martens

Family
Apiaceae
Season
Cool-season biennial grown as an annual
Best grown in
Portland, Oregon

A direct-sown root crop that needs loose, stone-free soil, patience during slow germination and thinning to final spacing.

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Life cycle & growth stages

  1. 1. SeedSow thinly, 5 mm deep, in stone-free soil.
  2. 2. GerminationSlow: 7–21 days; keep surface moist.
  3. 3. ThinningThin to 5–8 cm when 5 cm tall; remove thinnings to deter carrot fly.
  4. 4. Mid-growthFeathery tops 25–40 cm; roots lengthen.
  5. 5. Developing rootShoulders show at the surface.
  6. 6. Harvest readyShoulders 2 cm wide; colour at crown.
  7. 7. HarvestLoosen with a fork and pull by the tops.

Growth stages are ordered chronologically; timing varies with cultivar, temperature, light and care.

Planting calendar for Portland, Oregon

direct sow 3 weeks before to 6 weeks after last frost; 60–80 days to maturity from sowing. Windows are derived from the region's average frost dates (last Apr 5, first Nov 5) and are estimates until you confirm your own dates in the calendar.

CarrotDaucus carota subsp. sativus
PlantStart indoorsDirect sowAutumn sowTransplantTendHarvest
Carrot—Mar 15–May 17 (estimate); May 17–Aug 23 (estimate)Aug 13–Aug 27 (estimate)——May 14–Dec 23 (estimate)
  • Direct sow: Mar 15 – May 17
  • Harvest: May 14 – Dec 23
  • Succession sow: May 17 – Aug 23
  • Autumn sowing: Aug 13 – Aug 27

Spacing & support

In-row 5–8 cm; rows 30–40 cm. Planner footprint: 1 cell of 30 cm, 16 plants per cell.

Side-profile diagram of mature carrot: canopy 25–40 cm tall, 10–15 cm wide, deep root zone, support and harvest-access envelope.

Soil & water

Soil
Deep, loose, stone-free sandy loam
pH
6–6.8
Fertility
low
Water
Keep seedbed moist until emergence; then steady, moderate water to avoid splitting.
Frost
hardy; tolerates frost

Support & training

No support structure needed.

Carrot mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.

Harvest signs

  • Shoulders 1.5–2.5 cm across at the soil surface
  • Good colour at the crown
  • Pull a test root; flavour improves after light frost
Carrot at harvest readiness, showing the visual cues: shoulders 1.5–2.5 cm across at the soil surface; good colour at the crown.

Common problems

Pests: carrot rust fly, aphids, wireworm

Diseases: Alternaria leaf blight, cavity spot

Appearance alone is not a diagnosis; confirm with a regional extension guide.

Side-by-side: healthy carrot leaf or fruit and an example of Alternaria leaf blight.

Container growing

  • Minimum 10 L (30 cm deep)
  • Use quality potting mix and water more frequently
  • Choose short or round cultivars for containers under 30 cm deep.
Mature carrot in a correctly sized container (10 L or more) with drainage visible.

Companion overview

10 reviewed relationship records (evidence: medium).

Supported or conditional

Lettuce, French marigold, Onion, Radish

Avoid or separate

None with evidence

Traditional claims only: Chives, Rosemary, Tomato.

3 popular pairings reviewed with no verified relationship.

Full companion profile

Crop rotation

Avoid planting carrot or other carrot family crops in the same spot for 2 years. Rotation is about previous seasons, not about live neighbours.

Year 1Year 2Year 3ApiaceaeOther familyOther familyback after 2+ years

Shared risks in Apiaceae: carrot rust fly, Alternaria leaf blight, parsley worm (swallowtail caterpillar).

Crop rotation hub

Sources, reviewer & update

Sources

Reviewer: Garden Planner editorial team (pending independent horticultural review)

Last reviewed: August 15, 2026 · version 1

Found an error or have feedback? Let us know.

Growing carrot

Carrots are sown where they will grow; their taproot does not transplant. Seed is slow (1–3 weeks) and needs the surface kept moist, which is why a board or fleece over the row until emergence is a common trick. Sow from a few weeks before the last frost through midsummer for autumn roots.

Carrot seed beside a ruler or coin for scale.
Carrot seedling at cotyledon and first-true-leaf stage, in soil, distinguishable from common weeds.
Carrot mid-season before harvest, showing branching, vining, rosette or upright habit and space occupied.

Forked or stunted roots come from stony, compacted or freshly manured soil, not from companions. Thin to 5–8 cm between plants; crowded carrots stay thin. The feathery tops are only 25–40 cm tall, so carrots fit between taller crops without shading them.

Two or more mature carrot plants with a tape measure showing in-row spacing (5–8 cm).
Carrot flower detail or bolting stage.
Immature root of carrot developing on the plant.

Carrot rust fly is the main pest in many regions; the documented protection is a fine mesh barrier or timing sowings to miss egg-laying peaks. The traditional onion pairing has only conditional field support at very high onion ratios.

Edible parts and safety

Edible: root, leaves (sparingly).

Hands or tool harvesting carrot correctly (cut, pull, twist or pick) without damaging the plant.

Pests and diseases

Common pests: carrot rust fly, aphids, wireworm. Common diseases: Alternaria leaf blight, cavity spot. These vary by region; a photograph is an example, not a diagnosis. See the pest and disease guides and your local extension service.

carrot rust fly on carrot, with a wider damage-context view.

Timeline

Season timeline for carrot: sowing, transplanting, flowering, harvest and bed occupancy aligned to frost dates.Text alternative: Direct sow Mar 15–May 17; Harvest May 14–Dec 23; Succession sow May 17–Aug 23; Autumn sowing Aug 13–Aug 27.

Related plants

See also: Apiaceae family page · crop rotation · regional calendar · guides

Our Methodology & Sources

We synthesize peer-reviewed research, university extension publications, and trusted horticulture resources. Our evidence levels help you understand how strong the science is behind the guidance.

Evidence tiers

Supported evidenceConsistent results from multiple robust studies
Traditional claimHistorical use reported, limited scientific support
Context dependentMixed or variable results across conditions
No verified relationshipNo reliable evidence identified

Primary source types

  • Peer-reviewed journal articles
  • University extension publications
  • Government & research institute reports
  • Systematic reviews & meta-analyses

Last updated

August 24, 2026

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