What to Plant With Broccoli: Broccoli and Cabbage Companion Plants

Broccoli belongs to the cabbage family, along with cabbage, cauliflower, kale, Brussels sprouts and collards. Companion lists usually treat the whole group together, so what works next to broccoli generally works next to its relatives too. Our kale guide covers the leafy side of the family. Broccoli is a cool-season crop that goes out weeks before the last spring frost, or in midsummer for a fall harvest, which makes it a natural partner for other early crops. Here is what extension sources list and how to fit it in.

Good companion plants for broccoli

Onions and beets

Virginia Extension lists the onion family and beets as cabbage-family companions. All three are cool-season crops planted in early spring, so they share a bed and a schedule well. Onions are slim and upright and fit in the gaps between broccoli plants. See what to plant with onions.

Potatoes

Potatoes are also on Virginia Extension's companion list for the cabbage family. Both go in early in spring. Leave room between rows for hilling the potatoes. More in what to plant with potatoes.

Lettuce as a filler

Lettuce is not on the cabbage-family companion list in our sources, but University of Maryland Extension recommends interplanting lettuce between rows of later-maturing crops such as broccoli and tomatoes as a space saver. The lettuce is cut before the broccoli needs the room. See what to plant with lettuce.

What not to plant with broccoli

Virginia Extension lists tomatoes and strawberries as incompatible with cabbage-family crops. Tomatoes are also a summer crop that would shade spring broccoli as it grows, so a separate bed makes sense anyway. Our tomato guide covers tomato neighbors, and every pair to separate is in the keep-apart chart.

Where sources disagree: dill and spinach

Dill is the interesting one. Penn State Extension notes that dill can discourage cabbageworms from laying eggs on cabbage-family plants, while Virginia Extension lists dill as incompatible with the group. If you want to try dill, plant a few at the end of the row rather than among the broccoli, and keep it away from carrots, which are a listed poor match for dill.

Rotate the whole cabbage family

UMN Extension recommends growing broccoli where you have not grown any related crop, including cabbage, cauliflower, Brussels sprouts, collards, kale, mustard, turnip or rutabaga, for the past four years. Diseases such as clubroot and black rot affect the whole group, so moving the family around the garden matters more than any single neighbor.

Planting and spacing

• Spring crop: start seeds indoors. UMN Extension's Minnesota timing is early to mid-April, and seedlings are ready to harden off after about four weeks, once they have four or five true leaves. Our planting calendar gives a frost-based window for cabbage and broccoli wherever you live. For start and transplant dates by frost, see when to plant broccoli.
• Fall crop: start seeds indoors or sow outdoors in midsummer (July in Minnesota), so heads form as the weather cools. In mild-winter areas broccoli can go in as late as October or November; see what to plant in fall.
• Depth: a quarter to half an inch deep.
• Spacing: set transplants or thin seedlings to 8 to 10 inches apart.
• Soil: fertile, well-drained but moisture-retentive soil with a pH of 6 to 7, following a soil test. Side-dress when plants are about four inches tall.

A simple cool-season broccoli bed

1. Broccoli in the middle row.

   Plants 8 to 10 inches apart, with a row cover in the first weeks.

2. Onions along one side.

   A listed cabbage-family companion that takes little room.

3. Beets along the other side.

   Another listed companion with the same early schedule.

4. Lettuce tucked between broccoli plants.

   Harvested before the broccoli fills out.

Keep tomatoes and strawberries in other beds. Our raised bed layouts include a 4×4 cool-season bed you can adapt.

Watering, harvest and pests

Broccoli needs steady moisture to form sweet, firm heads; UMN Extension warns that water stress leads to small, off-flavored heads. If rain does not supply an inch a week, soak the soil thoroughly at least once a week, more often in sandy soil, and mulch three to four inches deep with weed-free straw or herbicide-free clippings.

Harvest while the head is still tight and before the flower buds open, cutting it with a short stalk. Leave the plant in place: smaller side shoots form afterward for a second harvest, and broccoli keeps growing after the first light fall frosts. The common pests are flea beetles and caterpillars such as the imported cabbageworm, cabbage looper and diamondback moth; a well-anchored row cover in the first weeks of growth helps protect young plants.

Broccoli in containers

Broccoli can grow in a large container with drainage holes, one plant per pot, in full sun. Because UMN Extension stresses steady moisture for good heads, check containers often, since they dry out faster than garden soil.

Frequently asked questions

What grows well with broccoli?

Extension-listed companions for broccoli in our checker are beets, celery, chard, onions and potatoes. As a cabbage-family crop, it shares its companion list with cabbage and kale. The table on this page explains why each pairing works.

What should you not plant with broccoli?

Our sources list strawberries and tomatoes as poor neighbors for broccoli. Sources disagree on dill and spinach.