Brussel sprouts are a delicious and nutritious vegetable in the Cruciferae family. They are a cool-season crop that can be vulnerable to many insect pests. They also need a number of nutrients while growing. Using companion planting can help with some of these problems and needs.
Why Do Brussel Sprouts Need Companion Plants?
If you are new to companion planting, you can read my article for everything you need to know about companion planting, below I will discuss the ways companion plants help Brussel Sprouts.
Brussel sprouts, like other members of the Cruciferae family, are vulnerable to a large number of insect and anthropoid pests. Many of the companion plants discussed below either repel insect pests or mask the odor of the Brussel sprouts so pests cannot find them. In addition, these aromatic plants are usually valuable in their own right.
Bring Pest Predators
Other crops attract predators to them to eat their own problem pests. When these plants are close to Brussel sprouts, the predators will spread out onto the Brussel sprouts and eat any pests there. When the pests are gone, the predators retreat to the companion plant until the next time pests get on the Brussel sprouts.
Some plants with long tap roots bring nutrients and water from deep in the soil to the root zone where Brussel sprouts can reach them. These plants bring up more than they need and spill the extra into the soil. When they are planted close to Brussel sprouts, the Brussel sprout can take these nutrients and water up to use for themselves.
Benefit from Brussel Sprouts
Some plants are grown with Brussel sprouts because the Brussel sprouts benefit them. Brussel sprouts, like many plants, excrete chemicals into the air and soil that can help other plants grow better. The shade the larger Brussel sprout plant offers can also be beneficial to other cool-season crops.
Top 10 Best Companion Plants for Brussel Sprouts
Here are the top ten companion plants for Brussel sprouts and what they do to help grow good crops of Brussel sprouts.
Sage is an aromatic herb that is grown both for cooking and for traditional medicines. This woody shrub has silvery green leaves that are picked to add flavor to meals. They can be used fresh or dried for later use. The essential oil in sage gives it a strong odor which most pests do not like. In particular, sage repels diamondback moths, other moths, and rust flies from Brussel sprouts. Sage can grow into a large shrub, so be sure to allow enough space between the small sage plant and the Brussel sprouts so that the mature sage is two to three feet from the Brussel sprouts. You don’t want the sage to shade the Brussel sprouts.
Dill is grown as a cooking and pickling spice. The flower heads and seeds are used to make dill pickles. Dill has green leaves and yellow flowers. Dill attracts predatory insects because it often has problems with dill aphids. It also serves as the nursery for caterpillars from the Black-tailed Swallowtail. Predators are attracted to these pests. When they eat all the pests on the dill, they spread to the Brussel sprouts and control pests there. Plant the dill in the next row, not in the same row as the Brussel sprouts.
Beets produce greens and roots to eat. These are both delicious and nutritious. Beetroots come in several colors, including black, white, orange, and the familiar red. The Chioggia beets look like bullseye targets with alternating white and red stripes. Beets have tap roots that can go down 36-48 inches, deep into the soil. Because of their extensive taproot, beets draw nutrients and water from deep in the soil. They excrete the extra nutrients and water into the soil. Brussel sprouts can then access it. Plant the beets in rows between rows of Brussel sprouts for the best results.
Peppermint is another aromantic plant used in cooking and medicine. The plants have green leaves and pinkish-lavender flowers. The leaves and flowers are used fresh or dried to flavor tea or sweets. Peppermint has a strong smell that repels aphids and flea beetles with its odor. Peppermint, like all mint, is invasive and should be grown in a pot set close to the Brussel sprouts or the peppermint will out-compete the Brussel sprouts.
Rosemary is an aromatic herb used in cooking and medicine. This woody shrub has green needle-like leaves and is an evergreen. Native to the Mediterranean area, rosemary is widely grown in warmer climates. Rosemary repels moths and rust flies with its odor. Rosemary is a shrub, so make sure you leave enough room in your garden for it when it is mature. Like sage, it will grow large and shade out the Brussel sprouts if you do not leave enough space between the two when planting.
The onion family contains onions, garlic, and leeks. They are used in cooking and medicine. All three plants have long green leaves and a strong odor. Because of these smells, they repel cabbage looper, imported cabbageworm, Japanese beetles, aphids, and blight. Plant the Brussel sprouts in rows next to onions, garlic, or leeks. The onion family needs to be planted first so that the plants are up and fragrant when the Brussel sprouts are planted.
Chard is related to beets. It is used as a potherb or in stir-fries. Chard has green or reddish leaves and stalks that can be red, white, or yellow. The leaves and stalks may be prepared separately in recipes. Chard is listed as a companion plant to Brussel sprouts because the Brussel sprouts help the chard grow better. Plant it in rows next to the Brussel sprouts.
Spinach is a green used fresh or cooked. Spinach is a cool-season crop with dark green leaves. Brussel sprouts help spinach grow better. It is low and can grow close to Brussel sprouts without interfering with them. The extra shade spinach gets from Brussel sprouts helps keep them cool and from bolting. Plant the spinach in the space between rows of Brussel sprouts.
Sunflowers are grown for their seeds. They have long green stalks, green leaves, and large flowers made up of smaller flowers to form a “false flower” that attracts pollinators. The center of the false flower is yellow and the rays coming from it can be yellow or maroon. They can provide partial shade from the hot sun for the broccoli. They are also pretty and attract pollinators. Seed varieties of sunflowers get quite large, so leave enough room for them when they are mature when planting them.
Nasturtiums are edible flowers with a peppery taste. They have rounded shield-shaped green leaves. The flowers come in many colors. Nasturtiums are native to Central and South America but are widely grown throughout the world. The oil in the flowers and leaves has a smell like watercress and repels cabbage looper, imported cabbageworm, squash bugs, and whiteflies. You can grow nasturtiums in the space between the rows of Brussel sprouts or in adjacent rows.
Top 4 Worst Companion Plants for Brussel Sprouts
Fennel is a vegetable grown for its fleshy base. It has yellow flowers and wavy leaves and resembles dill. Fennel exudes a toxic chemical that kills Brussel sprouts and anything else planted near it. Fennel needs its own little corner of the garden away from any other plants.
Strawberries are a common low plant that produces juicy berries. They have green leaves and white flowers. Strawberries secrete a chemical that inhibits the growth of Brussel sprouts. Put them on the other side of the garden as they inhibit all plants in the Cruciferae family.
Pole Beans are a popular vegetable. They require support to grow up such as a stake. Pole beans have green leaves and produce edible beans in pods. Pole beans’ growth is inhibited by Brussel sprouts. Do not plant the beans within five feet of Brussel sprouts.
Tomatoes are the most popular vegetable in the world. They have green leaves studded with hairs and yellow flowers. Brussel sprouts exude a chemical that inhibits the growth of tomatoes. Separate tomatoes by at least five feet from all members of the Cruciferae family.
In conclusion, there are plants that help Brussel sprouts grow better while other plants should not be planted with Brussel sprouts. Good companion plants include nasturtiums, sunflowers, spinach, chard, members of the onion family, rosemary, peppermint, beets, dill, and sage. Plant these plants within two to three feet of Brussel sprouts to act as companions. Brussel sprouts should not be planted with fennel, strawberries, pole beans, and tomatoes. Separate these plants by at least five feet so they do not interfere with each other. In fact, do not plant any members of the Cruciferae family within five feet of fennel, strawberries, pole beans, and tomatoes.