Record — updated 2026-07

Cabbage Companion Plants

Entry No. 008

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

The best companion plants for cabbage are Glossy Collard, White Clover, Radish, Indian Mustard, and Buckwheat. Avoid planting cabbage near Other cabbage-family crops, Strawberry, Tomato. Of the 12 pairings recorded here, 5 are supported by published research and 6 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 cabbage

Companion plants for cabbage — 5 research-backed, 3 traditional
Plant Claimed benefit Evidence What the evidence actually shows
Buckwheat Flowering buckwheat nearby increases parasitoids and predators of cabbageworm and aphids. Research-backed Extension cites trials showing buckwheat and cowpea raise natural-enemy numbers; the tested target was corn earworm, so the cabbage benefit follows the same mechanism rather than a dedicated trial.
Glossy Collard A two-row collard perimeter keeps diamondback moth out of the cabbage crop. Research-backed The single strongest brassica companion result. Across nine commercial cabbage fields the collard perimeter held diamondback moth below action thresholds while 60% of control fields exceeded them; growers cut insecticide sprays 56% and saved $117-156 per hectare. Leave about 60 cm between trap and cash crop, because heads within 30 cm of the trap weighed less.
Indian Mustard Indian mustard is far more attractive to diamondback moth than cabbage and diverts egg-laying. Research-backed In host-choice trials diamondback moths laid 18 times more eggs on Indian mustard than on cabbage; extension lists mustard, arugula, rapeseed and napa cabbage among effective brassica trap crops. Trap plants must be managed or they amplify the next generation.
Radish Radish and daikon sown ahead of cabbage act as flea beetle trap crops. Research-backed Multiple trials support radish and daikon as flea beetle traps; sow 1-2 weeks before the cabbage, allow roughly 10% of the area, and place the trap as a perimeter. Destroy it afterwards, since radish is itself a brassica and can host clubroot.
White Clover Cabbage undersown with white clover suffers far less pest colonization. Research-backed Directly demonstrated on cabbage: undersown plots produced commercially acceptable heads without insecticide, fungicide or herbicide, and Dutch trials found subclover and white clover suppressed egg-laying and larval populations enough to improve profit. Expect somewhat smaller heads from clover competition — the pesticide savings offset it.
Beet Beets fill the space between cabbage plants and share no significant pests with brassicas. Traditional Spatial and pest-separation logic only; no measured interaction, but a genuinely sensible pairing.
Dill Dill flowers feed the braconid and ichneumonid wasps that parasitise cabbageworms. Traditional A real and useful mechanism at the habitat level, but no controlled trial links dill plantings to measurably fewer caterpillars on cabbage.
Nasturtium Nasturtium acts as a sacrificial host pulling cabbage aphids off the crop. Traditional Plausible on chemistry — nasturtium shares brassica glucosinolates — and widely observed by gardeners, but no replicated trial was found. Trap plants must be removed once colonised.
Mint, sage, thyme and other aromatic herbs Pungent herbs are said to mask cabbage's scent and drive away cabbage root fly and cabbageworm. Not supported Tested and not supported. Across 24 non-host plants, aromatic species including mint, sage, thyme, marigold and onion were no more effective than non-aromatic ones at disrupting cabbage root fly, and green paper models releasing no chemicals performed as well as living clover. The protective effect comes from green ground cover interfering with landing, not from smell.

What not to plant with cabbage

Plants to keep away from cabbage
Plant Claimed problem Evidence What the evidence actually shows
Other cabbage-family crops Grouping brassicas concentrates clubroot, black rot, Fusarium yellows and the full pest complex. Traditional Well-founded rotation advice — clubroot spores persist in soil for a decade or more — though framed as a multi-season practice rather than a measured adjacency effect. Note the deliberate tension with brassica trap cropping, which relies on planting relatives nearby.
Strawberry Strawberries are traditionally said to inhibit cabbage growth. Traditional Appears in nearly every companion chart with no experimental basis; the two share no pest and no documented chemical interaction.
Tomato Tomatoes are said to stunt cabbage and compete heavily for nutrients. Traditional No supporting study; both are heavy feeders, so the advice reduces to ordinary competition rather than an established antagonism.

The honest verdict

Of everything gardeners recommend planting alongside cabbage, 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 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.

Widely repeated, not supported: Mint, sage, thyme and other aromatic herbs — Tested and not supported. Across 24 non-host plants, aromatic species including mint, sage, thyme, marigold and onion were no more effective than non-aromatic ones at disrupting cabbage root fly, and green paper models releasing no chemicals performed as well as living clover. The protective effect comes from green ground cover interfering with landing, not from smell.

Every row above links to the publication it came from. See how we grade evidence.

Growing cabbage: the numbers

Field data — Cabbage
SunFull sun (6+ hours)
WaterModerate
Spacing15 in apart · 30 in between rows · 1 per square foot
Mature sizeabout 18 in tall
Soil pH6–7
Days to maturity60–100 days
Frost toleranceHardy — takes hard frost
ContainersYes — 5 gallon minimum
Typical yield1 head, 1-3 lb early types to 4-8 lb storage types
Common pestsimported cabbageworm, cabbage looper, diamondback moth, cabbage maggot, cabbage aphid, harlequin bug, flea beetles
Common diseasesblack rot, Fusarium yellows, clubroot, blackleg, downy mildew, Alternaria leaf spot

When to plant cabbage

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

Start seeds indoors: Jan 30 – Feb 20 — 7–10 weeks before your last frost

Transplant outdoors: Mar 20 – Apr 2 — 3 weeks before last frost

Direct sow outdoors: Apr 10 – Apr 23 — around your last frost date

Expected harvest: May 19 – Jun 28 — 60–100 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

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 cabbage 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:

Cabbage companion planting questions

What should not be planted next to cabbage?
Other cabbage-family crops, Strawberry, Tomato. Grouping brassicas concentrates clubroot, black rot, Fusarium yellows and the full pest complex. Well-founded rotation advice — clubroot spores persist in soil for a decade or more — though framed as a multi-season practice rather than a measured adjacency effect. Note the deliberate tension with brassica trap cropping, which relies on planting relatives nearby.
How far apart should cabbage be planted?
Space cabbage about 15 inches apart in the row, with 30 inches between rows. In a square-foot bed that works out to 1 plant per square foot.
Does companion planting with cabbage 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 cabbage?
Start seed indoors 7–10 weeks before your last frost. Transplant outdoors 3 weeks before last frost. In zone 6b that means roughly Mar 20 – Apr 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.