Celery Companion Plants
Apium graveolens var. dulce · carrot family family · rotation group: other
The best companion plants for celery are Leek, Cabbage, Tomato, Bush bean, and Onion. Avoid planting celery near Corn, Carrot, Fennel. Of the 10 pairings recorded here, 1 is supported by published research and 9 are traditional practice with no controlled evidence behind them.
What to plant with celery
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Leek | Alternating rows of leek and celery smother weeds and produce more total yield per unit of ground than either crop alone. | Research-backed | Replicated Swiss field trials (Baumann, Kropff & Bastiaans, Weed Research 2000) cut weed soil cover about 41% and weed biomass about 58% versus leek alone and raised relative yield total about 10%, but leek quality was reduced; the demonstrated benefit is weed suppression and land-use efficiency, not pest control. |
| Bush bean | Bush beans are recommended alongside celery as a mutually beneficial pairing. | Traditional | A standard chart recommendation with no controlled evidence; any nitrogen fixed by the bean is largely retained in the bean plant and released only after the residue breaks down, so a same-season fertility transfer to celery has not been demonstrated. |
| Cabbage | Celery interplanted with cabbage-family crops is said to repel cabbage white butterfly and reduce caterpillar damage. | Traditional | Extension companion charts do pair celery with the cabbage family, but no controlled trial testing celery against Pieris rapae or any other brassica pest could be found; the 'celery repels cabbage white butterfly' line appears only in gardening literature repeating itself. |
| Nasturtium | Nasturtium planted near celery is said to draw aphids away from the crop. | Traditional | UMN Extension summarizes trials in which nasturtium reduced squash bug and cucumber beetle damage in cucurbits and cabbage looper damage in broccoli, but nasturtium has not been tested with celery and there is no published aphid-diversion result for this pairing. |
| Onion | Onion volatiles growing beside celery are said to confuse pests that locate carrot-family crops by smell. | Traditional | The underlying mechanism is real for carrots — Uvah & Coaker (1984) found mixed cropping carrots with onions reduced carrot fly attack, attributed to onion volatiles disrupting host-plant finding while the onions were young — but celery has never been the tested partner, so extending it to celery is inference, not evidence. |
| Spinach | Fast, low-growing spinach uses the space between slow celery transplants before the celery canopy closes. | Traditional | A spacing and timing convenience rather than a biological interaction; no trial has measured a pest, disease, or yield benefit from the combination, and both crops compete for the same steady water supply. |
| Tomato | Celery grown near tomatoes is said to improve tomato growth and flavor. | Traditional | Listed on extension companion charts with no measured pest, yield, or flavor effect reported anywhere; both crops are heavy feeders that demand steady moisture, so the pairing is at best neutral and can increase competition. |
What not to plant with celery
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Carrot | Carrots should not be grown immediately beside or in rotation with celery. | Traditional | Not a demonstrated antagonism: celery and carrot are both Apiaceae and share pest and disease pressure, so ordinary rotation practice separates them. No companion-planting trial has tested growing them side by side, and no yield penalty has been measured. |
| Corn | Corn is widely listed as the one crop to keep away from celery. | Traditional | WVU Extension's chart lists corn under 'avoid' for celery with no mechanism given and no supporting trial; the plausible rationale is simple shading and nitrogen competition from a tall, heavy-feeding neighbor, not any chemical antagonism. |
| Fennel | Fennel is said to release compounds that inhibit celery and most other garden vegetables. | Traditional | A broad allelopathy claim with no measured mechanism for celery; UMN Extension warns that long published lists of repellent and antagonistic plants 'are not always accurate or backed by research', and no study of fennel against celery was found. |
The honest verdict
Of everything gardeners recommend planting alongside celery, 1 pairing has been tested properly: Leek. Those are the ones worth planning your bed around.
The remaining 6 pairings on this page are traditional practice. They circulate on every companion planting chart online, but we could not find controlled evidence testing them. They are not wrong so much as unverified — most cost nothing to try, and interplanting flowers and herbs has its own well-documented benefit of pulling pollinators and predatory insects into the garden.
Every row above links to the publication it came from. See how we grade evidence.
Growing celery: the numbers
| Sun | Full sun (6+ hours) |
|---|---|
| Water | High — keep evenly moist |
| Spacing | 8 in apart · 18 in between rows · 4 per square foot |
| Mature size | about 24 in tall |
| Soil pH | 6–7 |
| Days to maturity | 100–130 days |
| Frost tolerance | Half-hardy — takes a light frost |
| Containers | Yes — 3 gallon minimum |
| Typical yield | 1 bunch |
| Common pests | aphids, cabbage looper, imported cabbageworm, tarnished plant bug, two-spotted spider mite, leafminers, cutworm, armyworm, slugs and snails |
| Common diseases | fusarium yellows, cercospora and septoria leaf blight, sclerotinia pink rot, cucumber mosaic virus, tomato spotted wilt virus, blackheart (calcium deficiency) |
When to plant celery
Zone 6b shownStart seeds indoors: Jan 16 – Jan 30 — 10–12 weeks before your last frost
Transplant outdoors: Apr 24 – May 7 — 2 weeks after last frost
Expected harvest: Aug 2 – Sep 1 — 100–130 days from planting
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seeds- Tango — Vigorous, adaptable green celery with tender stalks; the usual home-garden pick because it is less demanding than older types.
- Utah 52-70 — Standard open-pollinated green Pascal-type listed by Texas AgriLife Extension; thick, tightly folded stalks.
- Conquistador — Widely grown commercial green type listed by Texas AgriLife Extension; tolerant of warmer conditions than most celery.
- Command — One of the Fusarium yellows-resistant varieties recommended by UC Master Gardeners where the disease is established (with Mission and Challenger).
Variety names link to seeds on Amazon. As an Amazon Associate we earn from qualifying purchases. These are the varieties named in the extension sources for this crop, not a paid placement — where a source recommended a variety for a specific reason, that reason is the note beside it.
Put it in a bed
The garden planner checks every square against this ledger as you place crops — if you drop celery next to something recorded as a bad neighbour, the square turns red and tells you why.
Records for the plants named above:
Same rotation group (other) — don't follow one with another:
Celery companion planting questions
What should not be planted next to celery?
How far apart should celery be planted?
Does companion planting with celery actually work?
When should I plant celery?
Sources for this record
- Penn State Extension (York County Master Gardeners) — Vegetable Seed Planting Guide
- UMass Extension Vegetable Program — Celery
- Texas A&M AgriLife Extension (J. Masabni) — Celery
- UC Marin Master Gardeners — Celery
- UNH Extension — Growing Vegetables: When to Plant Your Vegetable Garden
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.