Experienced organic gardeners bring diversity and balance to the garden with the age-old wisdom of companion planting, a time-tested method of close planting specific species based on their propensity to enhance each other’s growth and quality. Companion planting can help you grow a thriving crop of delicious, healthy broccoli.
Companion plants offer shade or shelter, conserve moisture, control weeds, enrich flavor, or provide some form of disease or insect protection. Companion plants, with differing nutritional needs, also work harmoniously to balance nutrient levels in the soil.
When choosing plants for companion planting, consider selecting non-competitive plants with differing nutritional needs and growth habits. Companion planting is an especially important gardening technique when trying to use space efficiently in a small garden.
Best Companion Plants For Broccoli
For optimum flavor, plant broccoli near celery, onions, garlic, shallots, leeks, and potatoes. Other garden favorites that grow well planted alongside broccoli are beets, bush beans, dill, lettuce, spinach, rhubarb, cucumbers, Swiss chard, and radishes.
Fragrant culinary herbs such as lemon balm, lemon grass, thyme, sage, horehound, hyssop, basil, rosemary, tansy, oregano, chamomile, and mint help repel insect pests (e.g. harlequin bugs, cabbage worms, cabbage loppers, and cabbage maggots) that can quickly devastate a broccoli crop.
Nasturtiums, marigolds, snapdragons, and cosmos emit a scent that is repulsive to many garden pests including cabbage worms, whiteflies, flea beetles, cabbage root maggots, and aphids. These colorful blooming plants help keep the garden free of insects without the use of noxious chemical insecticides while adding color, scent, and visual interest to the homestead garden plot.
Unfriendly Neighbors For Broccoli
Broccoli, one of the most nutritious of all vegetables, gets along well with most of its neighbors: more plant species flourish when planted close to broccoli than fail. Broccoli’s only problem is getting along with its own family, especially in poor soil conditions.
Broccoli is a heavy feeder, preferring loamy, well-drained, fertile soil. However, broccoli is not fussy and grows just fine in sandy or clay soils enriched to enhance fertility. Other members of the cruciferous plant family Brassica (Brassica oleracea), which includes cabbage, cauliflower, collard greens, kale, kohlrabi, and Brussels sprouts, compete for the same nutrients as broccoli. Planting them together with broccoli results in nutritional deficiencies in the soil.
Competing members of the Brassica family will fight to the death for nutrients. Unless continually supplemented with well-aged herbivore manures (e.g. sheep, goat, cow, or horse), few soils contain enough essential nutrients to grow broccoli alongside other members of the Brassica plant family.
Pumpkins, squash, sweet corn, watermelon, strawberries, pole beans, lima beans, snap beans and asparagus are also heavy feeders, requiring nutrient-rich soil: calcium specifically is in high demand. Avoid planting broccoli next to these garden staples, which compete for the same nutrients as broccoli. Grapes and mustard plants, when planted next to broccoli, also negatively impact the growth of the broccoli plant.
Broccoli fails to flourish when planted near members of the nightshade family, like tomatoes, hot peppers, and eggplant.
Preparing The Soil For Broccoli
Broccoli grows best in a full-sun, although it will do well in partial shade. Choose a well-drained location with fertile soil with a pH of 6.0-7.0, a pH level that discourages clubfoot disease.
Testing kits for soil pH levels are available online or from local home and garden stores, or you may take a soil sample to your local county extension office for testing. Amend soil as recommended. When soil is low in boron, broccoli can develop hollow stems. Amend if the soil test indicates a deficiency in the mineral.
Because broccoli is such a heavy feeder, growth and flavor are enhanced when soil is supplemented with a generous amount of nitrogen-rich manure, cottonseed meal, or garden compost. Before planting broccoli seedling, break up the soil to a depth of at least one foot, removing rocks, roots, weeds, and debris. Work in manure and add a substantial amount of peat moss to help conserve moisture.
Tips For Growing Broccoli
Available in a diverse array of colors including white, green and purple, broccoli is easy to grow with minimal attention. My favorite broccoli varieties include Arcadia, Captain, Di Cicco, Emerald Pride, Everest, Gypsy, Packman, and Windsor.
- Plant in seed trays indoors 4-6 weeks before the last frost. Sow seed at a depth of about 1/8 inch in a mixture of one part potting soil, one part peat moss, and one part garden sand. Keep potting soil uniformly moist, but not soggy. If allowed to dry out, seedlings will bolt and become inedible.
- Broccoli seeds need lots of light for best germination. Place potting trays in a bright and sunny location or provide supplement lighting.
- If the seed is sown outdoors, broccoli can germinate in cool soil temperatures of 40 degrees Fahrenheit or above. For spring planting, experience gardeners suggest seeding or setting transplants three weeks before the last frost date. For a winter crop, seed or set transplants in late summer.
- In about six weeks, when seedlings are sturdy enough to transplant, transfer to the garden, planting broccoli plants approximately 18 inches apart. Space rows 18-24 inches apart.
- Mulch broccoli plants with a four inch layer of straw or dried grass clippings or ground leaves to conserve moisture. Broccoli demands consistent moisture to produce solid, flavorful heads.
- Keep a watchful eye out for white cabbage butterflies and promptly remove eggs and caterpillars.
- Once established, broccoli requires 1.5-2 inches of water per week: supplement if rainfall is inadequate
- Disease problems you might encounter when growing broccoli include clubfoot, black leg and black rot. Consult with the experts at your local county extension office for more information on organic pest management.
For optimum growth and flavor, broccoli requires a large amount of calcium. Successful broccoli growers suggest supplementing soil with regular applications of bone meal or other calcium-rich organic garden supplements, so that the soil contains plenty of calcium throughout the growing season. Apply approximately one pound of blood meal when seedlings are 8-10 inches tall and again every 3-4 weeks as the growing season progresses.
Broccoli has some frost tolerance and grows well in United States Plant Hardiness Zones 3 through 9. Being a cool-season vegetable, broccoli matures in less than eight weeks. Broccoli grows best at temperatures from 60-70 degrees Fahrenheit.
When grown as a spring crop, it can be harvested, and vegetation cleared to make room for a fall crop. In zones 7 through 9, broccoli is cultivated as a winter crop. Broccoli does not do well when temperatures exceed 75 degrees Fahrenheit.
During mid to late summer, it is difficult to grow quality broccoli, due to the adverse effects of low soil moisture together with higher soil temperatures. If you wish to try to grow broccoli in the summer, access to irrigation is essential.
When tiny flower heads are beginning to form at the center of the plant, watch the growth daily. Harvest when buds are tightly closed. If allowed to develop yellow flower petals, the buds swell and have a mealy texture and diminished flavor.
To harvest, cut flower heads with a sharp knife. To reap a second harvest, allow the plant to continue to grow after the first cutting of the main flower head. Additional shoots or smaller flower heads will develop at the axis of the leaves. Many gardeners report the second harvest of small immature flower heads is sweeter and florets more tender than the first cutting.
Broccoli is at its peak when consumed fresh from the garden. For short-term storage (3-5 days), mist unwashed heads and wrap in a damp paper towel for storage in the refrigerator crisper.
When ready to use, wash broccoli in warm water in a large bowl to which you have added a quarter cup of white vinegar. Soak for 10-15 minutes to remove soil and debris and to kill any insect pests that may be hidden in the tightly packed florets. Remove, rinse with cold water, and dry thoroughly with a paper towel.
Do not store broccoli in a plastic bag or sealed container. Broccoli requires fresh air to retain flavor and texture. Stored improperly, broccoli can go from crisp and flavorful to limp and bland in just a day or two.
Broccoli can be frozen, canned or dehydrated for winter storage.
Broccoli Production, Penn State Extension Service
Gardening Solutions, University Of Florida
Broccoli, National Gardening Association