Record — updated 2026-07

Brussels Sprouts Companion Plants

Entry No. 006

Brassica oleracea var. gemmifera · brassica family · rotation group: brassica

The best companion plants for brussels sprouts are Glossy Collard, White Clover, Radish, Indian Mustard, and Buckwheat. Avoid planting brussels sprouts near Other cabbage-family crops, Strawberry, Tomato, Pole Bean. Of the 13 pairings recorded here, 5 are supported by published research and 8 are traditional practice with no controlled evidence behind them.

Research-backed tested in controlled research Traditional long practice, untested Not supported tested and not supported

What to plant with brussels sprouts

Companion plants for brussels sprouts — 5 research-backed, 4 traditional
Plant Claimed benefit Evidence What the evidence actually shows
Buckwheat Buckwheat borders raise populations of parasitoids and predators over the long growing season. Research-backed Extension cites trials showing flowering buckwheat and cowpea increase natural enemies; the long Brussels sprouts season gives beneficials time to build up, which is the main argument for it here.
Glossy Collard A collard perimeter absorbs diamondback moth pressure across the long Brussels sprouts season. Research-backed The perimeter trap crop is proven in cole crops and is especially valuable here because Brussels sprouts occupy the ground for 90-110 days, accumulating far more pest pressure than a quick cabbage crop.
Indian Mustard Indian mustard attracts diamondback moth egg-laying far more strongly than the cash crop. Research-backed Host-choice trials recorded 18 times more eggs on Indian mustard than on cabbage, and yellow rocket produced zero larval survival; the trap must be managed or it becomes a nursery.
Radish Radish sown ahead of the transplants diverts flea beetles from young Brussels sprouts. Research-backed Supported by replicated flea beetle trap-crop trials; sow 1-2 weeks early and destroy the trap, since radish is a brassica and can host clubroot.
White Clover A clover living mulch between the widely spaced stalks reduces pest colonization. Research-backed Demonstrated in brassicas at Warwick Crop Centre; the wide spacing and long season of Brussels sprouts suit an undersown mulch better than most cole crops, though clover competition still costs some yield.
Beet Beets occupy the ground between young stalks and share no pests with the cabbage family. Traditional Spatial pairing only; harvest the beets before the sprout canopy closes.
Dill Dill in flower feeds the parasitic wasps that attack cabbageworm and looper larvae. Traditional Habitat mechanism is real; no controlled trial ties dill to lower caterpillar counts on Brussels sprouts.
Sage Sage and thyme interplanted with Brussels sprouts reduce diamondback moth. Traditional Sources genuinely conflict. University of Minnesota Extension lists sage and thyme reducing diamondback moth on Brussels sprouts among research-supported claims, while a peer-reviewed review of the primary trials reports sage and thyme showed no difference in diamondback moth oviposition. Given Finch and Collier found aromatic plants no better than non-aromatic ones generally, treat this as unproven.
Spinach Fast spring greens are harvested from between the transplants long before the stalks fill in. Traditional A genuine use of the wide spacing and long establishment period, with no biological interaction claimed.

What not to plant with brussels sprouts

Plants to keep away from brussels sprouts
Plant Claimed problem Evidence What the evidence actually shows
Other cabbage-family crops Neighbouring brassicas concentrate clubroot, black rot and the full caterpillar and aphid complex. Traditional Standard rotation advice, and more consequential here than for quick crops because the plants stand in the ground for three to four months of continuous exposure.
Pole Bean Pole beans shade the tall stalks and are said to reduce sprout set. Traditional Generic light competition; Brussels sprouts do need full sun to set tight sprouts, so crowding is a real practical concern even though the specific pairing is untested.
Strawberry Strawberries are traditionally said to inhibit Brussels sprouts. Traditional Repeated everywhere, supported nowhere; no trial evidence exists for this pairing.
Tomato Tomatoes are said to compete heavily with Brussels sprouts for nutrients. Traditional No study found; both are long-season heavy feeders, so this reduces to ordinary competition rather than a documented antagonism.

The honest verdict

Of everything gardeners recommend planting alongside brussels sprouts, 5 pairings have been tested properly: Glossy Collard, White Clover, Radish, Indian Mustard, Buckwheat. Those are the ones worth planning your bed around.

The remaining 4 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 brussels sprouts: the numbers

Field data — Brussels Sprouts
SunFull sun (6+ hours)
WaterModerate
Spacing18 in apart · 32 in between rows · 1 per square foot
Mature sizeabout 30 in tall
Soil pH6.2–6.8
Days to maturity85–110 days
Frost toleranceHardy — takes hard frost
ContainersYes — 7 gallon minimum
Typical yield40-80 sprouts up a single stalk, harvested bottom-up
Common pestscabbage looper, imported cabbageworm, cabbage aphid, diamondback moth, flea beetles, cabbage maggot
Common diseasesAlternaria leaf spot, black rot, blackleg, clubroot, Fusarium yellows

When to plant brussels sprouts

Zone 6b shown
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F
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A
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Start indoors Sow / transplant outdoors Harvest

Transplant outdoors: Jun 19 – Jul 2 — 10 weeks after last frost

Fall planting: Jul 21 – Aug 3 — 14 weeks before your first fall frost

Expected harvest: Sep 12 – Oct 7 — 85–110 days from planting

Those dates are for zone 6b. Get your own dates by ZIP code →

Varieties worth knowing

seeds

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 brussels sprouts 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:

Brussels Sprouts companion planting questions

What should not be planted next to brussels sprouts?
Other cabbage-family crops, Strawberry, Tomato, Pole Bean. Neighbouring brassicas concentrate clubroot, black rot and the full caterpillar and aphid complex. Standard rotation advice, and more consequential here than for quick crops because the plants stand in the ground for three to four months of continuous exposure.
How far apart should brussels sprouts be planted?
Space brussels sprouts about 18 inches apart in the row, with 32 inches between rows. In a square-foot bed that works out to 1 plant per square foot.
Does companion planting with brussels sprouts actually work?
Partly. 5 of the pairings on this page are backed by published research — Glossy Collard, White Clover, Radish, Indian Mustard, Buckwheat. The rest are traditional practice: plausible, harmless to try, but untested. Treat the folklore as a starting point rather than a rule, and read what the evidence says about companion planting.
When should I plant brussels sprouts?
Transplant outdoors 10 weeks after last frost. In zone 6b that means roughly Jun 19 – Jul 2. Get exact dates for your ZIP code →

Sources for this record

Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.