Companion Planting for Broccoli: 8 Best Partners and What to Avoid (2026)

As an Amazon Associate I earn from qualifying purchases. This page may contain affiliate links.

Companion planting for broccoli can reduce pest pressure, attract beneficial insects and make better use of limited bed space, provided you choose the right partners. In this guide you will learn which plants pair well with broccoli, which ones to keep apart, how to lay out a bed so the plants do not compete for water and nutrients, and how to troubleshoot the problems that most often show up in the brassica patch.

Broccoli is a heavy feeder with a long growing season, and it is a favorite target of cabbage worms, aphids and flea beetles. Good companions will not replace crop rotation, healthy soil or regular monitoring, but they can make a real difference when they are planted with purpose. If you are new to the idea, our overview on What Does Companion Planting Mean? Pairings and Pitfalls explains the principles behind it.

Shopping for one? See our guide: Companion Planting with Pole Beans: 8 Best Supports, Companions and Tools (2026).

How Companion Planting Works with Broccoli

Companion planting for broccoli rests on three main mechanisms. Some plants release aromatic compounds that confuse or repel pests. Others produce flowers that feed predatory insects such as hoverflies, lacewings and parasitic wasps. A third group works underground, either by fixing nitrogen, by shading the soil to hold moisture, or by occupying space that weeds would otherwise fill.

Research on companion planting is mixed, and results vary with climate, soil and pest pressure. Treat companions as one layer of a pest management plan. Scout the undersides of leaves at least twice a week, and remove egg clusters by hand when you see them.

Key Factors to Consider

• Light: Broccoli needs at least six to eight hours of direct sun. Tall companions should sit on the north side of the bed so they do not shade the brassicas.
• Root depth: Pair broccoli with shallow-rooted plants so you do not create root competition in the same zone.
• Nutrient demand: Broccoli feeds heavily on nitrogen. Legumes help replace it, but avoid crowding them so the broccoli does not get outcompeted.
• Growth habit: Low, spreading companions make good living mulch. Upright plants need enough room to avoid leaning over the heads.

Best Companion Plants for Broccoli

The following plants have the most consistent reputation as broccoli companions in home gardens, and they are easy to fit into most vegetable beds.

Aromatic Herbs: Dill, Thyme and Rosemary

Dill attracts hoverflies and parasitic wasps, both of which prey on aphids. Plant it about 12 inches from the broccoli stem so its feathery top does not shade the crown. Let a few dill plants flower and set seed. Thyme makes a low ground cover along the bed edge, and many gardeners plant it near brassicas to deter cabbage moths. Rosemary is more tender and woody, so place it at the end of a bed where it will not be disturbed.

Aromatic Onion-Family Plants: Onions and Garlic

Onions and garlic emit sulfur compounds that some gardeners find helpful against certain brassica pests. Set bulbs 4 to 6 inches apart along the edge of the bed, roughly 10 to 12 inches from the broccoli. Keep them weeded, because onions are poor competitors. For a related pairing, see Onions and Lettuce Companion Planting: 8 Best Picks for Your Garden (2026).

Flowering Attractors: Marigolds and Alyssum

French marigolds (Tagetes patula) are widely planted for their root-zone effects on nematodes and their appeal to beneficial insects. Sweet alyssum is a low, fragrant annual that draws hoverflies and tiny parasitic wasps. Space alyssum about 6 inches apart along the front of the bed, and plant marigolds at the corners or between broccoli plants, leaving at least 12 inches from each crown.

Nitrogen Helpers: Bush Beans and Clover

Bush beans fix nitrogen through root nodules, which benefits heavy-feeding brassicas. Sow them 4 inches apart in a row at least 15 inches from the broccoli. White clover can serve as a living mulch between rows, but mow or pull it back from the stems so it does not compete for moisture. Keep an eye on slugs, which hide in dense ground cover.

Leafy Companions: Lettuce and Spinach

Lettuce and spinach are cool-season crops that mature quickly and fill gaps in the early part of the season. Sow lettuce in the spaces between young broccoli transplants, then harvest it before the broccoli canopy closes in. This use of interplanting is one of the most practical ways to get more food from a small bed. Our piece on Companion Planting with Lettuce: Best Pairings and Mistakes to Avoid covers timing in more detail.

Strong-Smelling Crops: Celery and Potatoes

Celery is often recommended as a companion because its strong scent may confuse some brassica pests. It needs consistent moisture, so water both crops on the same schedule. Potatoes can share space in larger beds, but plant them on the far side of a bed or in a separate block, since they compete for nutrients and can harbor certain diseases. For more on this pairing, read Companion Planting with Potatoes: 9 Best Plants and 5 to Avoid.

Plants to Keep Away from Broccoli

Some plants compete with broccoli or share pests and diseases that make problems worse. Avoid planting these within the same bed or within about 18 inches of the broccoli.

• Strawberries: They compete for space and can harbor pests and fungal problems that affect brassicas. Keep them in a separate bed.
• Other brassicas: Cabbage, kale, cauliflower and Brussels sprouts share the same pests and diseases, including clubroot and black rot. Rotate them instead of placing them together.
• Pole beans: They can shade and crowd broccoli if trellised too close. Give them their own trellis on the north side.
• Tomatoes: Tomatoes and brassicas can compete heavily for nutrients and create a dense, humid microclimate. Keep them in different beds.
• Fennel: Fennel is widely listed as an allelopathic plant that inhibits the growth of many neighbors, including broccoli.

Laying Out a Broccoli Bed with Companions

A well-planned layout matters as much as the choice of companions. In a raised bed, broccoli plants usually need 18 to 24 inches of spacing, depending on variety. Smaller heading types can sit closer, while large-headed varieties need more room. Use the spacing below as a starting point.

Step-by-Step Setup

1. Amend the bed with 2 to 3 inches of finished compost and test the soil pH. Broccoli prefers a range of about 6.0 to 7.0.
2. Mark the broccoli positions first, using 18 to 24 inches between plants and at least 24 inches between rows.
3. Place taller companions, such as bush beans or dill, on the north side of the bed.
4. Set low companions like alyssum and thyme along the south edge or between broccoli plants.
5. Transplant broccoli on schedule. For spring crops, start seeds indoors about 6 to 8 weeks before the last frost.
6. Water at the base of the plants, about 1 inch per week, and mulch lightly to keep roots cool.

Tools and Supplies Checklist

• Soil test kit or pH meter
• Finished compost
• Measuring tape or string with knots at 12, 18 and 24 inches
• Row cover to protect against cabbage moths
• Drip hose or soaker hose
• Hand trowel and garden gloves
• Seed-starting tray or transplants

Common Mistakes

• Overcrowding: Companions that shade or crowd broccoli reduce head size. Respect spacing, even for herbs.
• Assuming companions replace protection: Row cover and hand-picking are still the most reliable ways to control cabbage worms.
• Planting too many flowers: A few alyssum plants attract beneficial insects, but a crowded bed can harbor slugs and reduce airflow.
• Ignoring water needs: Thirsty companions such as celery will compete with broccoli if they are not watered on the same schedule.
• Skipping rotation: Companion planting does not solve clubroot or black rot. Rotate brassicas to a new bed every three to four years.

Tips for Success

• Start with two or three companions rather than trying to fill the whole bed at once.
• Keep a simple garden journal so you can see which pairings worked in your conditions.
• Let a few herbs and flowers go to seed. Many beneficial insects depend on them later in the season.
• For small spaces, try the square-foot approach described in Companion Planting for Raised Garden Beds: 8 Best Picks for 2026.
• Check soil moisture with a finger test before watering. Broccoli prefers deep, infrequent watering over daily sprinkling.

Recommended gear

The following supplies can make companion planting for broccoli easier to manage. Look for the same product type as listed, and choose sizes that suit your bed.

• Insect row cover: A lightweight fabric that blocks cabbage moths from laying eggs on young plants. Lift it for pollination and weeding. View on Amazon
• Soaker hose: Delivers water at the root zone so the foliage stays dry, which helps reduce fungal problems. View on Amazon
• Soil pH test kit: Helps you confirm the bed is in the 6.0 to 7.0 range that broccoli prefers. View on Amazon
• Seed-starting tray with humidity dome: Useful for starting broccoli and alyssum indoors on schedule. View on Amazon

FAQ

What are the best companion plants for broccoli?

Dill, sweet alyssum, thyme, onions, garlic, bush beans and lettuce are among the most commonly recommended companions. Choose two or three that fit your bed and climate, and keep them at the proper spacing.

Can I plant broccoli and tomatoes together?

It is generally better to keep them apart. Tomatoes and brassicas compete heavily for nutrients and can create crowded, humid conditions that favor disease. Use separate beds when possible.

Does companion planting stop cabbage worms?

Companions may reduce pressure by attracting predatory insects, but they rarely eliminate cabbage worms on their own. Row cover, regular scouting and hand-picking remain the most dependable methods.

Is dill really good for broccoli?

Dill attracts hoverflies and parasitic wasps that feed on aphids and other soft-bodied pests. Let a few plants flower, and keep them about 12 inches from the broccoli so they do not shade it.

Should I plant garlic near broccoli?

Garlic can be a useful edge plant, and many gardeners include it for its sulfur compounds. Plant cloves 4 to 6 inches apart, about 10 to 12 inches from the broccoli, and keep them weeded.

What should I not plant next to broccoli?

Avoid strawberries, pole beans that can shade the crop, fennel, tomatoes, and other brassicas that share pests and diseases. Keep these in separate areas of the garden.

When should I plant companions with broccoli?

Plant broccoli transplants 2 to 4 weeks before the last spring frost, or in late summer for a fall crop. Sow companions like dill and bush beans once the soil has warmed, and interplant lettuce early so you can harvest it before the broccoli fills in.

Conclusion

Companion planting for broccoli works best when you choose a few partners with clear benefits, such as dill, alyssum and bush beans, and space them so they do not compete. Keep incompatible plants like strawberries and tomatoes in separate beds, and rotate your brassicas each year. Pair these habits with regular scouting and row cover, and your broccoli will be better protected from the pests that cause the most trouble.