Why Companion Planting Matters for Brussels Sprouts

Brussels sprouts sit in the garden for a long time — 80 to 100 days from transplant to harvest, sometimes longer. (For a full walkthrough of the growing Brussels sprouts timeline, see our growing guide.) That’s three to four months where they’re occupying space, drawing nutrients from the soil, and attracting every cabbage moth and aphid in the neighborhood.

Companion planting isn’t magic. It’s practical pest management and efficient use of garden real estate. Certain plants repel the specific insects that target brassicas. Others improve the soil. Some simply grow well in the same conditions without competing for the same resources.

The flip side is also true: some plants actively harm Brussels sprouts by attracting the same pests, competing for the same nutrients, or releasing chemicals that stunt growth.

Getting this right means fewer pest problems, healthier plants, and better use of your garden space.

Good Companions

Root Vegetables: Beets and Carrots

Brussels sprouts are heavy feeders with shallow-to-medium root systems. Beets and carrots feed at different soil depths, so they don’t compete for nutrients. Carrots also attract parasitic wasps, which prey on cabbage worms — one of the worst Brussels sprout pests.

Plant beets and carrots between your Brussels sprout rows or around the perimeter. They’ll be harvested long before the sprouts reach full size, freeing up space when the plants need it most.

Aromatic Herbs: Dill and Chamomile

Dill is a powerhouse companion for any brassica. It attracts hoverflies and lacewings, both of which eat aphids by the hundreds. It also draws in parasitic wasps that target cabbage worms.

Plant dill near your Brussels sprouts but not directly at the base — it needs its own light. A row of dill 12 to 18 inches away works well.

Chamomile improves the flavor and growth of nearby brassicas (gardeners have observed this for centuries, and there’s some research backing it up). It also attracts beneficial insects and accumulates calcium, potassium, and sulfur in the soil when its spent plants decompose.

Pest-Repelling Flowers: Marigolds and Nasturtiums

Marigolds are the most-studied companion plant in existence. French marigolds in particular release compounds from their roots that repel nematodes. Above ground, their strong scent confuses pests looking for brassicas by smell.

Plant marigolds in a border around your Brussels sprout patch. They’ll bloom from early summer through frost, providing continuous pest protection and attracting pollinators.

Nasturtiums serve a different role: they’re a trap crop. Aphids prefer nasturtiums over almost anything else in the garden. Plant them nearby, and the aphids congregate on the nasturtiums instead of your sprouts. When the nasturtiums get heavily infested, pull them out and dispose of them. Problem relocated.

Alliums: Onions, Garlic, and Chives

The allium family repels a wide range of pests. Their sulfur compounds mask the scent of brassicas, making it harder for cabbage moths to locate your sprouts. Onions and garlic also have mild antifungal properties that benefit neighboring plants.

Interplant individual onion or garlic plants between Brussels sprout transplants. Chives work well as a border planting — they’re perennial, so they’ll come back year after year.

Potatoes

An old-school pairing that works well in practice. Potatoes are deep-rooted and feed at a different soil level than Brussels sprouts. The two crops don’t share major pests. And because potatoes come out of the ground by mid-to-late summer, they free up space right when Brussels sprouts are entering their main growth phase.

Other Good Companions

• Celery: Its strong scent repels cabbage white butterflies.
• Spinach and lettuce: Low-growing, fast-maturing crops that make good use of the space between young Brussels sprout transplants before the sprouts fill in.
• Thyme and sage: Aromatic herbs that deter cabbage moths with their strong essential oils.

Bad Companions

Strawberries

Strawberries and brassicas don’t mix. Both are susceptible to similar fungal diseases, and planting them together increases the risk of cross-contamination. Strawberries also attract slugs, which will happily move over to your Brussels sprouts for dessert.

Keep at least 4 feet between strawberry beds and any brassica planting.

Tomatoes (and Other Nightshades)

Tomatoes and Brussels sprouts are both heavy feeders that demand a lot of the same soil nutrients — particularly nitrogen and calcium. Growing them side by side results in both crops underperforming.

Tomatoes are also tall and dense, and can shade out Brussels sprouts during the critical early growth phase when the plants need maximum sunlight.

Peppers and eggplant fall into the same category. Give nightshades and brassicas their own separate areas.

Other Brassicas (Too Close Together)

Planting Brussels sprouts right next to cabbage, broccoli, cauliflower, or kale seems logical — same family, same care, easy to manage. But clustering brassicas creates a pest magnet. Cabbage moths, flea beetles, and aphids find a concentrated buffet instead of isolated targets.

You can grow multiple brassicas in the same garden, just space them out. Mix other plant families between them to break up the scent trail that pests follow.

Pole Beans and Runner Beans

While bush beans are generally fine, pole beans and runner beans can be problematic. They grow tall and vigorous, potentially shading Brussels sprouts. Some gardeners also report that the two crops seem to stunt each other’s growth, though the mechanism isn’t well understood.

Layout Suggestions

Raised Bed (4x8 feet)

A standard 4x8 raised bed can fit 4 Brussels sprout plants comfortably (they need 18-24 inches between plants).

• Center two rows: 4 Brussels sprout plants, 2 per row, staggered
• Between plants: Onion sets or garlic cloves (3-4 between each sprout)
• Short ends: Dill on one end, chamomile or a few marigolds on the other
• Edges: Nasturtiums trailing over the sides, or a border of chives

The root vegetables and alliums come out first, giving the sprouts room to expand as they grow taller through summer and fall.

Raised Bed (4x4 feet)

Smaller bed? You can fit 2 Brussels sprout plants.

• Two sprouts planted diagonally, 20 inches apart
• Remaining corners: Marigolds in one, dill in another, onion sets in the other two
• Edge: Low-growing herbs like thyme

In-Ground Row Garden

For a traditional row garden:

• Main row: Brussels sprouts spaced 24 inches apart in the row, rows 30 inches apart
• Between rows: Alternate with rows of carrots, beets, or onions
• Row ends: Clumps of marigolds or nasturtiums
• Nearby: A patch of dill within 2-3 feet but not shading the sprouts

Succession Planting

Because Brussels sprouts occupy their space for so long, succession planting around them works well:

1. Spring: Plant lettuce and spinach between young sprout transplants. These fast crops mature and are harvested before the sprouts need the space.
2. Early summer: After pulling lettuce, tuck in onion sets or beet seeds.
3. Late summer: Once those are harvested, the Brussels sprouts have filled in and are heading toward their fall harvest.

Tips for Success

Don’t overthink it. Companion planting helps at the margins. It won’t save a crop from poor soil, insufficient water, or the wrong climate. Nail the basics first — full sun, rich soil, consistent moisture — then use companions to fine-tune.

Rotate every year. Even with perfect companion planting, don’t grow Brussels sprouts (or any brassica) in the same spot two years in a row. Rotate on a 3-4 year cycle to prevent disease buildup in the soil. When harvest time comes, learn how to store Brussels sprouts to get the most out of your crop.

Observe your own garden. Regional differences matter. Your specific pest pressure, soil type, and microclimate may make certain companions more or less effective. Keep notes and adjust.

Plant flowers everywhere. Even beyond the specific companions listed above, a diverse garden with many flowering plants attracts beneficial insects that keep pest populations in check. Biodiversity is the best pest management strategy there is.

For everything else you need to know about this rewarding crop, see our complete guide to Brussels sprouts.