Companion planting can be defined as the close planting of different species based on their ability to enhance one another's growth or offer some form of pest protection or other advantages. Sometimes this is a matter of choosing plants with different growth habits that don't compete with one another or those that have different nutrient needs that make efficient use of soil. Strategic companion planting is especially important in small gardens or wherever careful space planning is needed.
Reasons to Grow Broccoli
Broccoli (Brassica oleracea) is a member of the cabbage family, along with cauliflower, Brussels sprouts, and collard greens. It is an excellent plant to grow, because not only is it one of the most nutritious of all vegetables, but it is fairly easy to maintain and lacking in fussiness. A cool-season vegetable, broccoli fully matures in only 6 to 8 weeks, and can then be cleared away to make room for a late summer/ fall crop. Or, in areas where the frost comes late, you can plant it again for a fall crop.
Broccoli dislikes temperatures higher than 75 F, so the midsummer is not the time for broccoli. Although it likes full sun, broccoli is one of the few vegetables that will produce decently in partial shade. And its soil needs are rather low-key: it does fairly well both in sandy soil and soils rich in clay—and everything in between. All told, broccoli is one of the more accommodating vegetables you can grow.
Broccoli doesn't mind having most other vegetables as close neighbors, and it rarely hinders others in their growth. The exceptions are plants with very heavy calcium needs, as broccoli does consume a lot of calcium from the soil (that's one of the things that makes broccoli such a good health food). Broccoli growers may want to consider bone meal or another calcium-rich soil amendment to areas of the garden that are growing broccoli.
Broccoli is a member of the cabbage (Cruciferae) family, and opinions are mixed on whether other members of this group (which includes cauliflower, cabbage, and Brussels sprouts) are good companions for broccoli. On the one hand, all these plants have similar needs for nutrients and watering, which means that planting them close to one another should be an effective strategy. Other experts, though, suggest that because many of the same pests feed on these plants, its best to keep them apart in the garden in order to discourage mass insect attacks.
Potatoes can have a negative effect on many vegetables, but not so with broccoli, which seems unaffected by being in close proximity to potatoes.
In general, it's best to interplant broccoli with plants that don't need a lot of room and which enjoy some shade in the late spring and early summer, when broccoli growth is most robust. Plants that fit this category include loose-leaf lettuce, spinach, Swiss chard, and radishes.
Beyond that, the list of good neighbors for broccoli is a large one. (Note: these recommendations also hold true for Brussels sprouts, a close cousin of broccoli.)
Plants That Help Broccoli Grow Better
Some plants actually help improve the flavor of broccoli when planted nearby:
Other plants that are an aromatic help to repel common garden pests that feed on broccoli:
Because broccoli is a notorious calcium-hog, plants that require little calcium are good companions:
Though the reasons aren't well understood, some other plants that broccoli seems to enjoy as neighbors include:
Plants to Avoid Near Broccoli
A few plants have the reputation for having a decidedly negative effect on the growth and flavor of broccoli. Beans, for example, tend to fix nitrogen in the soil, and this can be too rich for broccoli to tolerate. The rather short list of plants to avoid near broccoli include:
Some heavy-feeding plants are also not well suited for planting near broccoli, which is also a heavy feeder. For this reason, avoid these plants that will compete for nutrients: