Companion Plants for Cabbage
The best companion plants for cabbage repel cabbage worms and aphids. This US guide covers proven pairings, plants to avoid, and spacing in garden beds.
Key takeaways
- Nasturtium used as a trap crop at the bed perimeter attracts aphids away from cabbage—plant it outside the bed edge, not mixed between cabbages
- Dill and thyme attract parasitic wasps (Cotesia glomerata) that parasitize imported cabbageworm eggs and larvae directly on the plant
- Never plant other brassicas (broccoli, kale, kohlrabi) in the same bed as cabbage—they share every pest and disease and intensify pressure
- Marigolds (Tagetes patula) suppress root-knot nematodes in warm, sandy soils where nematode pressure is high in Zones 7–9
- Space cabbage 18–24 inches apart with companion plants between rows to maintain airflow and reduce fungal disease including clubroot
Why companion planting matters for cabbage
Cabbage and other brassicas attract some of the most damaging vegetable garden pests in the US—imported cabbageworm, cabbage looper, cabbage aphids, and flea beetles—and companion planting is one of the most effective ways to reduce pressure from all of them without pesticide applications.
Companion planting works through two mechanisms: pest confusing (aromatic plants that mask the scent of the cabbage so insects can’t locate it) and beneficial insect attraction (flowering plants that bring in wasps, hoverflies, and lacewings that eat or parasitize the target pests).
Not all companion planting relationships are equally supported by evidence. This guide focuses on pairings with documented effectiveness in US garden conditions.
The three biggest cabbage pests and what targets them
Before picking companion plants, it helps to know what you’re fighting.
| Pest | Appearance | Damage | Peak season |
|---|---|---|---|
| Imported cabbageworm (Pieris rapae) | White butterfly larvae; pale green caterpillar | Ragged holes through outer and inner leaves | Spring and fall |
| Cabbage looper (Trichoplusia ni) | Gray-brown moth larvae; pale green caterpillar | Similar to cabbageworm; also damages inner heads | Summer and fall |
| Cabbage aphids (Brevicoryne brassicae) | Powdery gray-green clusters | Stunted growth; black sooty mold; spread viruses | Spring and early summer |
| Flea beetles (Phyllotreta spp.) | Small shiny black beetles | Tiny round holes in leaves; worst on transplants | Spring |
| Clubroot (Plasmodiophora brassicae) | Soil-borne disease, not insect | Root swelling and collapse; no chemical fix | Cool, wet spring |
Companion planting addresses insects, not clubroot. If you have clubroot history in a bed, raise soil pH to 7.0–7.2 with lime and rotate brassicas to a new bed for 4–7 years. No companion plant resolves an established clubroot infection.
Best companion plants for cabbage
Dill
Dill (Anethum graveolens) is the single most effective functional companion for brassica crops. It attracts parasitic wasps—especially Cotesia glomerata, which parasitizes imported cabbageworm larvae, and braconid wasps that target cabbage loopers.
How it works: Adult parasitic wasps feed on nectar from dill’s flat flower heads (umbels). Females then seek out cabbageworm larvae nearby and lay eggs inside them. The larvae continue feeding until the wasp eggs hatch and consume them from within.
How to plant it: Place 2–3 mature dill plants in flower in a row at one end of your brassica bed. Dill in full bloom is most attractive to wasps—don’t harvest all the fronds before the plant flowers.
One caution: Do not plant dill near fennel. The two compete and cross-pollinate. Keep them 3+ feet apart.
Thyme
Thyme (Thymus spp.) is a low-growing, perennial herb whose strongly aromatic foliage masks the host-finding cues used by cabbage butterflies (Pieris rapae) to locate plants for egg-laying.
Research from Michigan State University’s integrated pest management program found significantly fewer cabbageworm eggs on plants adjacent to thyme compared to control plants without nearby aromatic herbs.
How to plant it: Edge your brassica bed with a 12-inch strip of thyme. It stays low (6–12 inches) and doesn’t compete for canopy space. Established thyme requires almost no care beyond occasional trimming to prevent woody center development.
Bonus: Thyme flowers attract parasitic wasps and native bees, adding the same beneficiary-attracting function as dill.
Nasturtium (as a trap crop)
Nasturtium (Tropaeolum majus) is one of the most misused companion plants in US gardens. It does not repel aphids from cabbage. It attracts them—and used correctly, that’s the point.
Trap crop method: Plant nasturtiums in a continuous row or cluster at the perimeter of your cabbage bed, 12–18 inches outside the outer edge of the last cabbage head. Aphids, attracted to nasturtiums, colonize them instead of your cabbage. You remove or destroy the nasturtiums when they’re heavily infested, taking the aphid population with them.
Mixing nasturtiums between cabbage plants does not work this way. You need physical separation so the trap crop pulls pests away, not toward, the bed.
Growing nasturtiums: Direct-sow after frost. They grow fast (35–45 days to bloom), tolerate poor soil, and thrive in full sun. Space transplants 12 inches apart at the bed perimeter.
Marigolds
French marigolds (Tagetes patula—the small-flowered type sold as bedding annuals) have documented activity against root-knot nematodes (Meloidogyne spp.) when planted densely and tilled into the soil at season end. A 2013 study from North Carolina State University confirmed this effect in sandy, warm soils where nematode pressure is highest.
Important distinction: The nematode-suppressing effect requires dense planting across the entire planting area and soil incorporation at season end. A few marigolds at the bed edge don’t provide nematode control—they’re an aesthetic addition that also attracts some beneficial insects.
If nematodes are a confirmed problem (root knobs on harvested roots are the sign): Plant a solid bed of French marigolds in July, till them under in September, wait 3–4 weeks, then plant fall brassicas in that area.
For general pest management, standard African marigolds (tall T. erecta) and French marigolds both attract hoverflies and some parasitic wasps, adding functional value beyond nematode control.
Celery
Celery planted alongside cabbage is one of the oldest US companion planting recommendations. The theory is that celery’s strong scent confuses white butterflies searching for brassica plants to lay eggs on.
Practical note: Celery and cabbage have similar water and nutrient demands, making them compatible bed companions from a cultural standpoint. Both are cool-season crops with overlapping spring and fall planting windows.
Spacing: Celery grows 18–24 inches tall and 12 inches wide. Plant one celery per 2–3 cabbage heads, spacing them evenly through the bed rather than in a single row.
Aromatic herbs: sage, rosemary, and mint
Sage and rosemary produce volatile aromatic compounds that research has linked to reduced host-finding success by cabbage-feeding insects.
How to use them:
- Rosemary is perennial in Zones 7–11; treat as an annual in colder zones.
- Sage is perennial in Zones 5–8. Both grow upright and don’t shade low-growing cabbage.
- Place 1 plant of either herb every 3–4 feet along the bed edge.
Mint: Strongly aromatic and reportedly effective at deterring cabbage worms and aphids. The problem is containment—mint spreads by underground runners and will overtake a garden bed within one growing season. Plant mint in a buried container or terracotta pot to contain roots before adding it near your brassicas.
What not to plant near cabbage
Other brassicas: The most damaging mistake. Placing broccoli, kale, cauliflower, kohlrabi, or Brussels sprouts in the same bed as cabbage doesn’t diversify the garden—it concentrates every pest and disease that targets brassicas into one location. Cabbage loopers, imported cabbageworm, clubroot, and black rot spread through brassica beds freely. Keep different brassica crops in separate beds with at least 4–6 feet separation, or better yet, separate rows.
Strawberries: Strawberries and cabbage compete for space and nutrients without providing mutual benefits. Cabbage also suppresses strawberry growth through allelopathic compounds in its root exudates.
Pole beans: Competition for vertical space and nitrogen creates issues in tight plantings. Bush beans are fine at the bed perimeter.
Fennel: Fennel is allelopathic—it suppresses most vegetable crops grown nearby, including brassicas. Keep fennel isolated to a separate container or bed edge far from the vegetable garden.
Spacing for companion planting in cabbage beds
Standard cabbage spacing is 18–24 inches between heads in rows 24–36 inches apart. Companion plant placement:
| Companion | Placement | Spacing |
|---|---|---|
| Dill | End of bed row | 1 plant per 4 feet of bed |
| Thyme | Bed edge border | Continuous strip; 6 inches between plants |
| Nasturtium (trap) | 12–18 inches outside bed perimeter | 12 inches between plants |
| Marigolds | Bed perimeter or between rows | 10–12 inches between plants |
| Celery | Within the bed | 1 per 2–3 cabbage heads |
| Sage / rosemary | Bed edge | 1 per 4 feet of bed |
Cabbage companion planting in fall gardens
Fall brassica plantings—common in Zones 5–7 where summer heat prevents spring success—benefit from companion planting in slightly different ways. Aphid pressure is lower in fall; cabbageworm pressure continues through September. Focus companion planting on:
- Dill (let go to flower for wasp habitat)
- Thyme border (perennial; established plants are in place for fall plantings)
- Row cover as a physical barrier supplement to companion planting—the most reliable protection against cabbageworm in fall when plants are still small
For companion plant selection organized by pest type and vegetable, our companion planting chart covers spacing and benefit documentation for all major US vegetable crops. Our kale companion plants guide covers brassica-specific companion planting in more detail, since kale faces the same pest complex as cabbage.
For general companion planting principles and how pairings are evaluated for effectiveness, our companion planting guide covers the research behind common claims and which pairings have the best evidence behind them.
The University of Kentucky College of Agriculture’s brassica pest management guide provides identification keys, population threshold information, and integrated pest management recommendations for cabbage and other brassica crops across the southeastern and mid-Atlantic US.
Sarah Mitchell is a Master Gardener and garden writer based in the Pacific Northwest. She has been growing food and flowers for over 15 years across USDA zones 7 and 8.