Brussels sprouts grow best alongside aromatic herbs, alliums, certain flowers, and root vegetables that either repel common brassica pests, improve soil nutrition, or attract beneficial insects. Because Brussels sprouts are heavy feeders that take months to mature, choosing the right neighbors can make a real difference in both pest pressure and harvest quality.
Herbs That Protect Against Pests
The biggest threat to Brussels sprouts is the cabbage white butterfly, whose larvae (cabbage worms) chew through leaves and weaken the plant. Aromatic herbs planted between or alongside your sprouts help mask their scent and confuse these butterflies. Dill is the standout performer here. It deters cabbage butterflies and attracts lacewings, which are voracious predators of cabbage worms. Gardeners who interplant dill with brassicas consistently report less caterpillar damage than those who don’t.
Rosemary, sage, oregano, and mint all serve a similar role, using strong scents to deter leaf-chewing insects. Basil pulls double duty by repelling thrips, tiny insects that suck the juices from young sprout leaves. Any of these herbs can be tucked between Brussels sprout plants or planted along the edges of a bed.
Mint deserves a quick caution: it spreads aggressively through underground runners. Plant it in a container sunk into the bed rather than directly in the soil, or it will take over.
Alliums for Flavor and Fungus Control
Garlic, onions, leeks, and shallots are excellent companions for Brussels sprouts. Their natural anti-fungal properties help protect the soil around brassica roots, and their sharp smell acts as an insect repellent. There’s also a flavor benefit: alliums planted near Brussels sprouts are reported to enhance the sweetness of the mature sprouts. Since alliums are shallow-rooted and Brussels sprouts root more deeply, the two crops don’t compete heavily for space or water. A row of onions or garlic bordering your sprouts is one of the simplest companion pairings you can set up.
Flowers for Pest Control
Nasturtiums and geraniums are the classic flower companions for all brassicas. Their peppery, astringent scent repels cabbage worms, cabbage loopers, and flea beetles. Nasturtiums also work as a “trap crop,” luring aphids away from your Brussels sprouts and onto themselves instead. You can sacrifice the nasturtiums or spray them down with water to knock off the aphids.
Sweet alyssum is another strong choice. Its tiny flowers attract large numbers of beneficial insects, including hoverflies and parasitic wasps that prey on aphids and caterpillars. Tucking sweet alyssum around the base of Brussels sprout plants creates a living mulch that also helps retain soil moisture, something Brussels sprouts need consistently. They require about one inch of water per week, and even more in sandy soil.
If you have room, sunflowers and cosmos attract lady beetles, lacewings, and various parasitic wasps that keep brassica pest populations in check. These flowers produce nectar and pollen that feed the adult stages of predatory insects, keeping them in your garden longer. Research from organic market gardens has shown that flowering plants in the carrot and aster families can attract dozens of species of beneficial wasps to a single plot.
Vegetables That Share Well
Beets are a particularly good vegetable companion. They add magnesium to the surrounding soil, a nutrient that Brussels sprouts need for healthy development. Since beets are root vegetables and Brussels sprouts grow tall, they don’t compete for light or above-ground space.
Beans and peas fix nitrogen from the air into the soil through bacteria on their roots, which benefits Brussels sprouts since they’re heavy nitrogen feeders. There’s a nuance worth knowing, though: too much nitrogen can push Brussels sprouts to produce lush, leafy growth at the expense of actual sprout formation. If you’re planting legumes alongside your sprouts, don’t also add high-nitrogen fertilizer. Let the beans or peas provide what the soil needs naturally, and the balance tends to work out well.
Carrots and other root vegetables with different rooting depths generally coexist fine with Brussels sprouts. Chamomile is sometimes planted nearby as a supposed flavor enhancer, but it spreads quickly and can crowd out other companions if you’re not vigilant about cutting it back.
What Not to Plant Nearby
Tomatoes are the most commonly cited enemy of Brussels sprouts, and for good reason. Both are heavy feeders that will strip the same nutrients from the soil, leaving neither plant with enough to thrive. The problem goes beyond competition, too. Brussels sprouts and other brassicas produce chemicals that can inhibit growth in tomatoes, peppers, and eggplants. Keep all nightshades well away from your brassica beds.
Other brassicas like cabbage, broccoli, and cauliflower are poor companions as well, not because they’re antagonistic, but because they attract the exact same pests and diseases. Clustering brassicas together creates a concentrated target for cabbage moths and can accelerate the spread of clubroot and other soil-borne diseases. If you grow multiple brassicas, spread them across different parts of the garden.
Strawberries are another plant to keep separate. They share some of the same fungal diseases as brassicas, and the low-growing strawberry plants can get shaded out as Brussels sprouts grow tall over the season.
Putting a Bed Together
Brussels sprouts prefer well-drained, fertile soil with a pH between 6 and 7, so any companions you choose should tolerate those same conditions. Most of the plants listed above do. A practical layout for a raised bed or garden row: plant Brussels sprouts at their full spacing (about 18 to 24 inches apart), tuck dill or basil between them, border the bed with onions or garlic, and let sweet alyssum or nasturtiums fill the edges. This gives you pest deterrence from the herbs and alliums, beneficial insect habitat from the flowers, and a clean use of space since none of these companions compete with Brussels sprouts for the same root zone or nutrients.
If you’re growing beans or peas alongside, a trellis at the north end of the bed keeps the legumes from shading your sprouts while still contributing nitrogen to the soil. Brussels sprouts take 80 to 100 days to mature, so plan your companions’ timing accordingly. Fast crops like lettuce and radishes can fill space early in the season before the sprouts need it.