Cabbage Companion Plants
Cabbage grows best alongside companions that pull their weight. Reliable partners include Dill, Sweet alyssum, Onion, and Thyme. Just as important is what to keep apart — avoid planting cabbage near Other brassicas / cole crops, Fennel, and Strawberry. Every pairing below comes with the specific reason behind it and how to stack them by layer and season.
Grow Cabbage with: Dill, Sweet alyssum, Onion, Thyme, and more below.
Keep it away from: Other brassicas / cole crops, Fennel, Strawberry.
Best companions for Cabbage
Each pairing below earns its place — the reason, when to plant it, and where it sits in the bed.
Dill's umbel flowers feed adult Cotesia glomerata parasitoid wasps and hoverflies; C. glomerata lays eggs inside imported cabbageworm (Pieris rapae) larvae, killing them from within.
Layout: Plant at bed edges and let it flower during cabbage's vegetative growth. Bolting dill is mildly allelopathic to brassicas, so keep it on the perimeter, not woven through the center.
Alyssum's tiny nectar-rich flowers draw syrphid (hoverfly) adults whose larvae are voracious predators of cabbage aphid (Brevicoryne brassicae); documented in interplanted broccoli by USDA-ARS (Brennan).
Layout: Sow between cabbage rows a few weeks after transplant so it is in full bloom when aphid colonies begin building.
Onion foliage releases alliaceous sulfur volatiles (allyl-propyl-disulphide) that mask cabbage odor and disrupt diamondback moth (Plutella xylostella) host-finding and oviposition; intercrop trials cut DBM larvae.
Layout: Set onions between cabbages the same season; upright tops share the bed without shading the crop.
Thyme's aromatic volatiles deter cabbage moths; in an Iowa study thyme+onion+nasturtium reduced cabbage looper and imported cabbageworm damage, and thyme lowered diamondback moth on Brussels sprouts in greenhouse trials.
Layout: Use as a low perennial edging around the cabbage bed; it persists season to season.
Aromatic sage foliage masks host-plant cues; sage and thyme together reduced diamondback moth (Plutella xylostella) populations on Brussels sprouts in greenhouse trials.
Layout: Plant as a woody perennial neighbor at bed margins (greenhouse-demonstrated; field effect less quantified).
Nasturtium shares mustard-oil (glucosinolate) chemistry with brassicas, pulling cabbage aphids and cabbage white egg-laying onto itself; part of the Iowa combo that lowered cabbageworm damage on cabbage.
Layout: Plant at bed margins as a sacrificial magnet; pull and destroy aphid-loaded plants before pests migrate to cabbage.
Undersowing cabbage with white clover disrupts cabbage root fly (Delia radicum) egg-laying via green-background confusion and shelters ground beetles that eat its eggs; trials cut root-fly pupae per plant.
Layout: Undersow once cabbage transplants are well established (about 4 weeks) so the clover does not outcompete young seedlings for water and nitrogen.
A collard/mustard border intercepts diamondback moth and flea beetles before they reach cabbage; the wasp Diadegma insulare parasitizes DBM concentrated on collards, keeping Florida cabbage below spray thresholds.
Layout: Plant the trap border 2-3 weeks earlier (or same time) as an outer perimeter ring so it is more attractive than the cabbage when pests arrive.
Bolted coriander's umbel flowers supply nectar to hoverflies and parasitic wasps; in a collard+dill+coriander+onion system it boosted natural-enemy numbers attacking diamondback moth and aphids.
Layout: Let a few plants bolt during cabbage growth for continuous bloom; succession-sow so something is always flowering.
Marigold emits limonene that repels whitefly (proven on tomato) and can act as a banker plant boosting natural enemies. Cabbage-specific results are mixed: Rutgers found no repellency for cabbage pests.
Layout: Dot through or edge the bed; treat as a general beneficial-insect and possible repellent plant rather than a proven cabbage-pest fix.
How to lay it out
Stack companions by layer so they share light, root space, and time instead of competing — the permaculture way to pack more into one bed.
Plants to avoid near Cabbage
All share clubroot (Plasmodiophora brassicae), black rot, and the cabbageworm/aphid/diamondback/root-fly complex; clustering them concentrates pests and pathogens and defeats the 4-7-year rotation clubroot requires.
Fennel is strongly allelopathic, exuding compounds that inhibit germination and growth of many neighbors; it is a poor companion for cabbage and most vegetables and is best isolated in its own spot.
Traditionally kept apart: heavy-feeding cabbage competes with shallow-rooted perennial strawberries for water and nitrogen, and the two share slug and snail pressure. Direct chemical antagonism between them is not well documented.
Both are heavy feeders that compete for nitrogen and bed space; the pairing is widely discouraged in companion-planting lore, though rigorous evidence of direct chemical antagonism is weak.