How to Grow Cabbage Organically

Updated November 5, 2026

Growing cabbage organically mostly comes down to prevention. Move cabbage-family crops to a new spot every year. Extension advice ranges from a 3-year rotation to a 5–7-year one where clubroot is in the soil. Put floating row cover over transplants on planting day and seal the edges. Cabbage doesn’t need pollinators, so the cover can stay on all season. Check leaves weekly and catch caterpillars while they’re small, either by hand or with Bt, which caterpillars have to eat to be affected. For fertility, work compost into the soil before planting and let a soil test guide what else you add. For planting dates and spacing, see how to grow cabbage.

Related: how to grow cabbage (timing, spacing, harvest) · organic broccoli · organic kale · cabbage-family companions.

Diseases

UMN lists the main troubles: flea beetles, imported cabbageworm / looper / diamondback moth larvae, cabbage maggots, “Black rot causes yellow triangles on the edge of leaves.”, and “Clubroot attacks the roots of cabbage”. UMD also lists harlequin bug, bolting, and edema (a disorder, not a disease) (UMD Extension). Clemson: “There is no control for black rot once it is established in a planting.” (Clemson HGIC).

Crop rotation: how many years?

Rotation years disagree — do not average. Use the longer band if clubroot is in the soil.

UMN cole-crop advice: rotate away from cabbage, cauliflower, broccoli, Brussels sprouts, collards, kale, mustard, turnips or rutabagas for at least four years (UMN Extension). UMass: brassica weeds harbor flea beetles and cut the value of rotation (UMass Extension).

Black rot (cultural)

Start with certified disease-free seed or transplants (Clemson, UMass). UMass: increase spacing to reduce leaf wetness, remove infected seedlings promptly, do not work wet plants, avoid overhead irrigation, practice a three-year rotation, control cruciferous weeds, and incorporate residues after harvest (UMass Extension).

Hot-water seed treatment for black rot

UW–Madison Extension says seed can carry black rot of crucifers such as cabbage and broccoli. Its treatment table lists cabbage at “Cabbage 122° 25” (°F, minutes) (UW–Madison Extension, table modified from Cornell). UMass also describes hot-water treatment and says to test a small sample for germination first — labeled separately from the UW table, not merged.

Clubroot (cultural)

UMass: club-like swellings on roots; plants may wilt by day and recover at night. Worse on cold, wet, acidic soils; spread by drainage water and infested soil on tools or shoes. Cultural steps: maintain a high pH with lime per a soil test, long 5–7 year brassica rotations, improve drainage, control brassica weeds, avoid moving infested soil, and raise transplants in clean soil or soilless media (UMass Extension). UMN targets a soil pH of about 6 to 7 for cabbage.

Fertilizer and rates

Organic fertility only on this page. Synthetic side-dress N-P-K formulas from conventional fertilizer guides are not recommended here.

Base fertility on a soil test. UMD: “Fertilizers should be applied based on laboratory soil test results and plant needs.”. UMD rates cabbage medium for nutrients: use starter fertilizer when transplanting, and side-dress three weeks later (UMD Extension). Penn State: cole crops are heavy feeders and benefit from organic matter (Penn State Extension) — medium vs heavy labels are shown, not averaged.

UMN: improve soil with well-rotted manure or compost in spring or fall; do not use fresh manure. With enough manure or compost you may not need additional fertilizer applications (UMN Extension).

Organic nitrogen rate (UMD): “The general N recommendation for vegetable crops is 2 pounds per 1,000 square feet”. UMD’s own conversion for cottonseed meal (6-2-1): “2.0 ÷ 0.06 = 33.3 pounds of cottonseed meal fertilizer per 1,000 square feet”. (UMD, Fertilizing Vegetable Gardens)

UMD: “Don’t fertilize too early in spring, since cool soil temperatures limit nutrient release from organic matter.” UMD also notes too much nitrogen may make plants more vulnerable to pest or disease problems. Use any fertilizer as the label directs. See organic fertilizer basics.

Frost timing

NDSU’s chart: start seeds indoors about 10 weeks before your last frost and transplant about 3 weeks before it (NDSU H1139). For dates counted from your own frost dates, use the ZIP planting planner and frost dates. Planting, spacing and harvest detail: how to grow cabbage.

Pests to watch for

Controls, evidence ratings and bee cautions are on our pest page; follow the links rather than repeating spray schedules here.

Row covers

Fit floating row covers at seeding or transplanting and seal the edges with soil or bags (UMN, UMass). UD: covers must be in place before adults or eggs are present, and secured so insects and wind cannot get under (UD Cooperative Extension). UD: “Row covers can be left on all season for crops that don’t require insect or wind pollination, including beans, brassicas (cabbage, kale, broccoli, brussels sprouts etc.), and potatoes.”. UMN: remove covers after harvest; covers can also protect heads if overnight lows drop below about 25°F. Cover clean transplants in a bed that has not recently grown cabbage-family crops — pests already in the soil can emerge under the cover.

Caterpillars and Bt

UMN: the imported cabbageworm is the most common caterpillar in gardens; treat while caterpillars are still small. Tell them apart: imported cabbageworm caterpillars “can grow up to 1 inch in length and are velvety green with faint yellow stripes running lengthwise down the back and sides.”; cabbage loopers “have no legs in their middle sections and make a characteristic looping motion”; diamondback moth larvae are much smaller and wiggle vigorously when touched (UMN Extension).

Organic IPM order (UMN): scout both sides of leaves weekly; destroy crop residue and remove mustard-family weeds; row cover from transplant day; handpick into soapy water; rely on predators and parasitoids; if needed, use Bt — “Caterpillars must eat it to be effective. Get good coverage on the leaves when spraying.”. UMN: Bt is highly effective on small caterpillars while preserving parasitoids and natural enemies. Always follow the product label. More options and bee cautions: cabbage worms on the pest page.

Flea beetles

UMN: flea beetles chew small holes in leaves; seedlings are most vulnerable. Treat seedlings at more than about five beetles per plant; summer treatment usually isn’t needed once plants reach the 4–5-leaf stage (UMN Extension). UMass: row cover sealed at all edges right after seeding or transplanting gives excellent protection (UMass Extension). Flea beetles on the pest page · all cole-crop pests.

• Cabbage worms: green caterpillars chew holes in leaves and heads.
• Flea beetles: tiny beetles pit young leaves with shot holes.
• All cole-crop pests: the cole crop list on the pest page.

Saving seed

UW–Madison Extension: cole crops “(including broccoli, cauliflower, cabbage, Brussels sprouts, and kale) must be isolated from other members in their families.” (UW–Madison Extension).

More organic guides: Organic gardening hub · Organic pest control · Organic fertilizer · how to grow cauliflower.