Celery

Apium graveolens

Apiaceae

Leek

Allium ampeloprasum var. porrum

Amaryllidaceae

Can you plant celery and leeks together?

Yes. Celery and leeks grow well together. A shared bed gave about 19% more harvest than separate beds in one field trial, and celery competed less with leeks than expected in a field trial. That rests on two studies, so treat it as a lead, not a rule.

Why celery and leeks work together

More harvest from the same bed. In one field trial, a bed with both crops gave about 19% more harvest than the same space split into a celery bed and a leek bed.
Competition and crop performance in a leek-celery intercropping system (Baumann · 2001)
Less competition. In a field trial, celery competed less with leeks than expected.
Effects of Intercropping on Growth and Reproductive Capacity of Late-emerging Senecio vulgaris L., with Special Reference to Competition for Light. (Baumann DT · 2001 · Annals of botany)
Garden charts recommend it. 2 garden chart entries recommend growing them together. None of them cites a source. Charts pass on gardening tradition; they are not tests.
List of companion plants (uncited entry) (Wikipedia)

What to plant with celery and leeks

Good neighbours of both, best tested first.

CabbageWith celery: 27% more harvestWith leeks: 16% more harvest
TomatoWith celery: Recommended by garden charts, not testedWith leeks: Less disease

How each one was tested, with the evidence

What to keep away from celery and leeks

LettuceWith celery: Garden charts advise against it, not tested
Sweet cornWith celery: Garden charts advise against it, not tested
Swiss chardWith leeks: Garden charts advise against it, not tested

The evidence in detail

For readers who want to dig in: every chart entry, study and yield trial behind the answer above, with the numbers.

Tradition, research and yield trials

Tradition

Good

avoidgood

2 chart entries: 2 recommend, 0 advise against.

0 cited, 2 uncited.

Research

Good

avoidgood

1 paper found: 1 positive, 0 negative.

competition

auto-classified not reviewed by a person

Yield trial

Good

No per-crop split reported in these trials.

1 field trial. Published LERs lean high.

Good neighbours

What happens above and below ground

Each animation illustrates a mechanism a study reported for this pair. Pick a card to focus on it.

Everything at once.

What is going on (2)

Pick a card to spotlight its animation in the scene.

Celery LeekCelery and Leek compete for light, water and nutrients; the studies report mixed outcomes.

Researchfield trial x1

Effects of Intercropping on Growth and Reproductive Capacity of Late-emerging Senecio vulgaris L., with Special Reference to Competition for Light. (Baumann DT · 2001 · Annals of botany)

Celery LeekMedian land equivalent ratio 1.19 over 1 trial: growing them together gave 1.19 times the harvest of two separate plots of the same size.

Partial LERs (medians): Celery 0.60 + Leek 0.60. Range across treatments 1.10 to 1.56. Medians are taken separately, so the parts need not add up to the median LER. LER above 1 is biased upward by publication bias.

Yield trialfield trial x1

Competition and crop performance in a leek-celery intercropping system (Baumann · 2001)

Tradition saysGood

2 gardening-lore entries, 2 without a specific citation. Lore is a starting point, not proof.

None of the 2 tradition entries cite a specific source.

Companion plants for both celery and leeks

Plants that are good neighbours of each. Biggest harvest gain first; each cell links to the evidence for that pair.

Plant	With celery	With leeks
Cabbage	27% more harvest from the same spaceField trial, 1 study. Charts: recommend.Evidence for celery and cabbage	16% more harvest from the same spaceField trial, 1 study. Charts: not listed.Evidence for leeks and cabbage
Tomato	No trial foundNot tested. Charts: recommend.Evidence for celery and tomatoes	Less disease and better soil and nutrient uptakeGreenhouse or pot trial, 2 studies. Charts: recommend.Evidence for leeks and tomatoes

Harvest from the same space compares a bed with both crops against the same area split into single-crop beds, counting the harvest of both crops (the land equivalent ratio in yield trials).

The evidence, with sources

ResearchGood1 entry

Goodcompetitionfield trialauto-classified

Celery helps Leek
Effects of Intercropping on Growth and Reproductive Capacity of Late-emerging Senecio vulgaris L., with Special Reference to Competition for Light.
Effects of Intercropping on Growth and Reproductive Capacity of Late-emerging Senecio vulgaris L., with Special Reference to Competition for Light. (Baumann DT · 2001 · Annals of botany)

Relevance 88% · effect confidence 22%

Yield trialGood1 entry

GoodLER 1.19field trial

Switzerland, 1995; Replacement design; median LER 1.19 over 3 treatment(s)
Competition and crop performance in a leek-celery intercropping system (Baumann · 2001)

TraditionGood2 entries

GoodLeek helps Celery
Celery: helped by leeks
List of companion plants (uncited entry) (Wikipedia)
GoodLeek helps Celery
Leek: helps celery
List of companion plants (uncited entry) (Wikipedia)

Plan a bed with celery and leeks

All neighbours of celery and of leek, or every pair at once in the companion planting chart.

Have you grown celery and leeks together?

Tell other gardeners what happened: spacing, pests, harvest, or ask a question. Reader notes are not checked by us and do not change the verdicts on this page.