Leek growing profile.

Leek Companion Plants

What may help, what can compete, and where the evidence is still uncertain.

Leek Allium ampeloprasum (Porrum Group)

Cool-season vegetable in the onion family. View plant profile →

Quick answer

No reviewed study supports a specific beneficial companion for leek yet. 1 popular pairing has no verified relationship, which is not the same as safe or harmful.

Every status below has a direction, mechanism, context and source. "No verified relationship" means we looked and found nothing usable; the planner then evaluates spacing, light, water and timing normally. How we classify evidence →

No verified relationship (1)

Zero score and an honest unknown state. Spacing, light, water and timing are evaluated normally.

No verified relationship: we did not find a source that establishes a benefit or harm for these pairs. This is not the same as "compatible".

CarrotDaucus carota subsp. sativusNo verified relationshipOther Leek and Carrot affect each other (mutual)Spring–Fall · arrangement unspecifiedUnknown Review: August 15, 2026

Why?

Claim. We did not find a source that establishes a benefit or harm between leek and carrot.

Mechanism. None documented.

Conditions. Planted together Both plants must be present at the same time.

Applies when. 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.

Evidence. Unknown: No source meeting the inclusion rules. (none).

Sources. University of Minnesota Extension 2023

Reviewed August 15, 2026 by Garden Planner editorial team (pending independent horticultural review). Record leek--carrot--other v1. Request a correction.

Example layout for leek

No supported or conditional relationship specifies a layout. Space leek at 15–15 cm and plan by light, water and timing.

**Side view of leek (45–60 cm) beside typical companions, showing canopy, support, shade and access.**

When these companions overlap

Bed occupancy in Portland, Oregon (estimates). A relationship only matters while both plants are present.

Leek

Carrot37 wk overlap

Overlap in weeks
Carrot	37 weeks

Crop rotation guidance

Rotation is about what occupied the bed in previous seasons and is calculated separately from the live companion relationships above.

Rotate leek on a 3-year cycle with other onion family crops (Onion, Garlic, Chives). Shared risks: onion white rot, downy mildew, onion fly.

Crop rotation hub · Amaryllidaceae family page

Physical and resource fit

No significant light, water, pH or sprawl conflicts with the listed companions at recommended spacing.

Fit checks come from plant attributes and apply even when a pairing has a positive claim.

Community observations (anecdotal)

These reports come from gardeners and are not reviewed evidence. Results vary with soil, climate and practice. Community data never changes an evidence tier or a planner score.

Reports for leek: 0 (community submissions open in a later phase; drafts are stored only on your device).

**Community-submitted photo area (moderated) with context fields: region, season, layout, varieties, outcome.**

Record an observation

Evidence summary and sources

Companion planting in home gardens — University of Minnesota Extension, 2023 (guidance)

Reviewer: Garden Planner editorial team (pending independent horticultural review). Status counts on the Companions A–Z page are derived from these records. Corrections.

Leek Companion Plants

Quick answer

No verified relationship (1)

No records match those filters

Example layout for leek

When these companions overlap

Crop rotation guidance

Physical and resource fit

Community observations (anecdotal)

Evidence summary and sources

Related

Visual evidence on this page

Our Methodology & Sources