Cauliflower Companion Plants
Brassica oleracea var. botrytis · brassica family · rotation group: brassica
The best companion plants for cauliflower are Glossy Collard, White Clover, Radish, Mustard, and Buckwheat. Avoid planting cauliflower near Other cabbage-family crops, Strawberry, Pole Bean, Tomato. Of the 12 pairings recorded here, 5 are supported by published research and 7 are traditional practice with no controlled evidence behind them.
What to plant with cauliflower
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Buckwheat | Buckwheat borders build up parasitoid and predator populations near the crop. | Research-backed | Trials cited by extension show flowering buckwheat and cowpea increase natural enemies; the effect on cauliflower pests specifically has not been quantified. |
| Glossy Collard | A collard perimeter intercepts diamondback moth before it reaches the cauliflower. | Research-backed | The perimeter trap crop system is proven on cabbage and cole crops generally — moths lay far more eggs on glossy collards while larval survival there is only 6.7% versus 22.2% on cabbage. Trials used cabbage as the cash crop, so applying it to cauliflower is a reasonable but untested extension. |
| Mustard | Mustard, arugula and napa cabbage work as trap crops for the brassica pest complex. | Research-backed | Named by extension among effective brassica trap crops; must be managed or destroyed so the trap does not become a nursery. |
| Radish | Radish sown early diverts flea beetles from young cauliflower transplants. | Research-backed | Supported by replicated flea beetle trap-cropping trials; sow 1-2 weeks ahead, dedicate roughly 10% of the area, and destroy the trap crop rather than leaving it as a clubroot host. |
| White Clover | A clover living mulch reduces the number of pests that successfully colonise the crop. | Research-backed | Demonstrated across brassicas at Warwick Crop Centre. Use with caution on cauliflower specifically: it is the least forgiving cole crop and any check to growth from clover competition or water stress causes buttoning and poor curd quality. |
| Beet | Beets use the shallow soil between cauliflower plants without competing for the same rooting zone. | Traditional | Spatial only; sensible because the families share no pest, but no measured benefit. |
| Dill | Flowering dill supports parasitic wasps that attack cabbageworm and looper larvae. | Traditional | The habitat mechanism is sound, but no trial links dill to reduced caterpillar damage on cauliflower. |
| Spinach | Spinach is harvested from between cauliflower transplants before the plants close in. | Traditional | A spacing and scheduling benefit with no biological claim; the two share no significant pests. |
What not to plant with cauliflower
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Other cabbage-family crops | Neighbouring brassicas concentrate clubroot, black rot and the shared pest complex. | Traditional | Standard extension rotation guidance; the multi-year clubroot risk is real and well documented, the single-season adjacency penalty is not quantified. |
| Pole Bean | Pole beans shade cauliflower and are said to check its growth. | Traditional | Generic competition rather than a specific antagonism, though cauliflower is unusually sensitive to any growth check, which makes crowding a genuine practical concern. |
| Strawberry | Strawberries are traditionally listed as suppressing cauliflower. | Traditional | Ubiquitous in companion charts, entirely unsupported by any trial. |
| Tomato | Tomatoes are said to compete with cauliflower for nutrients and water. | Traditional | No study found; both are demanding crops and cauliflower needs uninterrupted moisture, so the advice is really about resource competition. |
The honest verdict
Of everything gardeners recommend planting alongside cauliflower, 5 pairings have been tested properly: Glossy Collard, White Clover, Radish, Mustard, Buckwheat. Those are the ones worth planning your bed around.
The remaining 3 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 cauliflower: the numbers
| Sun | Full sun (6+ hours) |
|---|---|
| Water | High — keep evenly moist |
| Spacing | 18 in apart · 30 in between rows · 1 per square foot |
| Mature size | about 24 in tall |
| Soil pH | 6–7 |
| Days to maturity | 50–80 days |
| Frost tolerance | Half-hardy — takes a light frost |
| Containers | Yes — 5 gallon minimum |
| Typical yield | 1 head, 6-12 in across |
| Common pests | imported cabbageworm, cabbage looper, diamondback moth, cabbage aphid, cabbage maggot, flea beetles |
| Common diseases | black rot, Alternaria brown spot, downy mildew, clubroot, bacterial soft rot |
When to plant cauliflower
Zone 6b shownStart seeds indoors: Feb 6 – Feb 27 — 6–9 weeks before your last frost
Transplant outdoors: Mar 27 – Apr 9 — 2 weeks before last frost
Expected harvest: May 16 – Jun 15 — 50–80 days from planting
Fall planting: Jul 28 – Aug 10 — 13 weeks before your first fall frost
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seeds- Snow Crown — 50 days, fastest and most forgiving, best choice for beginners
- Self Blanche — 60 days, leaves wrap the curd naturally so no tying is needed
- Amazing — 65 days, holds condition well, dependable fall type
- Violet Queen / Romanesco — purple and chartreuse specialty types, colour holds without blanching
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 cauliflower 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 (brassica) — don't follow one with another:
Cauliflower companion planting questions
What should not be planted next to cauliflower?
How far apart should cauliflower be planted?
Does companion planting with cauliflower actually work?
When should I plant cauliflower?
Sources for this record
- Growing cauliflower in home gardens — University of Minnesota Extension
- Cauliflower — Clemson Cooperative Extension HGIC
- How to Grow Cauliflower in Your Garden — Utah State University Extension
- Soil Temperature Conditions for Vegetable Seed Germination (GN 154) — UC Agriculture and Natural Resources
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.