Broccoli Companion Plants: the Good, Bad, and Best

Broccoli (Brassica oleracea var. italica) is not the easiest vegetable to grow but it is worth the effort. Timing is key when planting this cool-weather crop but despite your best efforts, it can be a hit or miss when unseasonably warm weather affects its growth. Its finicky nature makes it all the more important to choose the right neighbors for your broccoli—and follow the number one gardening rule of crop rotation by never planting broccoli or other cruciferous vegetables in the same location as the year before.

We've relied on research from agricultural universities across the United States to bring you the latest information on the best results in companion planting. However, many worst and best companion lists you'll see shared online are based on gardeners’ observations and experiences rather than on hard scientific data.

Benefits of Having Broccoli Companion Plants

When planning your garden, it makes perfect sense to let the principle of companion planting guide you because several plants have benefits for broccoli. Broccoli does well near plants that attract beneficial insects, such as predators that consume pests, thus keeping their populations down. Other companion plants deter hungry wildlife with their pungent smell, or they repel insect pests. 

Broccoli also benefits when it’s planted next to a crop that does not compete with it for nutrients, or, even better, a plant that improves the supply, availability, and uptake of nutrients from the soil.

The size and growth habits of companion plants can equally benefit broccoli. Tall plants can provide shade, which becomes increasingly important as the season progresses because broccoli does not like being exposed to the hot sun. Neighboring plants with lush foliage can also cast welcome shade on broccoli plants, reduce weed growth, and keep the soil cool and moist.

Best Broccoli Companion Plants

Although there is no scientific evidence to back this claim, some gardeners feel that the following vegetables improve the flavor of broccoli:

• Celery
• Potatoes
• Onions

Fragrant herbs act as aromatics to help repel common garden pests that feed on broccoli. In an Iowa study, thyme, onion, and nasturtium helped to reduce cabbage looper and imported cabbageworm damage in broccoli. Try to leave at least a portion of the herb plant untouched so it blooms because the pollen and nectar attract beneficial insects. For example, oregano flowers attract lacewings, which eat cabbage worms. Good herb companion plants for broccoli include: 

• Basil
• Chives
• Dill
• Mint
• Oregano
• Rosemary
• Sage
• Thyme

In general, it is best to interplant broccoli with plants that do not need a lot of space, or plants that enjoy some shade in the late spring and early summer when broccoli growth is most robust. Plants that fit this category include:

• Beets
• Cucumbers
• Garlic
• Lettuce
• Onions
• Radishes
• Spinach
• Shallots
• Swiss chard

In the annual flower category, nasturtiums and marigolds are the top companion plants for broccoli because they lure hungry caterpillars away from broccoli and other brassicas.

Worst Broccoli Companion Plants

Plants that grow very tall and bushy or spread, such as large vines, are not recommended as neighbors for broccoli. These include:

• Tomatoes 
• Eggplant
• Lima beans
• Peppers
• Pole beans
  
• Snap beans 
• Squash 
• Strawberries

Other crops that are not suitable because they are heavy feeders and can compete with broccoli for nutrients in the soil include:

• Asparagus
• Cantaloupe 
• Fennel
• Sweet corn 
• Pumpkin
• Watermelon

Companion Planting Broccoli with Other Brassicas

Opinions are divided on whether other members of the Brassica family (cabbage, Brussels sprouts, cauliflower, etc.) are good companions for broccoli. What speaks for them as companion plants is that all these plants have similar needs for nutrients and watering, which means that planting them close to one another is an effective strategy.

But because many of the same pests, such as cabbage worms, feed on these plants, you can also find the opposite approach, which would be the recommendation to keep them apart in the garden to discourage mass insect attacks. The good test is to plant a few brassica plants near each other to see how they thrive. As a safeguard, plant “trap plants” such as nasturtium or marigold next to them so that the cabbageworm caterpillars flock to them instead.