Broccoli and cauliflower both belong to the cabbage, or cole, family. Other commonly grown cole crops include brussels sprouts, collards, kale, kohlrabi and cabbage.

Climatic Requirements:

Cole crops are cool-weather vegetables, growing best when daytime temperatures are between 65 and 80 degrees F. Cauliflower is more sensitive to hot weather than broccoli. In the Northeast, broccoli is grown as a spring and fall crop, while cauliflower does best when planted in mid-summer for a fall harvest.

Both broccoli and cauliflower tend to do better when set out as transplants rather than planted from seed. It is important to use sturdy transplants that will become established quickly.

Soil Requirements:

All of the cole crops grow well in reasonably fertile, well-drained, moist soils with plenty of added organic matter. A mulch will help keep the ground cool and moist. The pH should be between 6.0 and 7.0 for optimum growth. A pH within this range will discourage clubroot disease and maximize nutrient availability.

Fertilizers:

Fertilizer and lime are best applied using the results of a soil test as a guide. As a general guideline, 2 to 3 pounds of 8-16-16 fertilizer applied uniformly over 100 square feet of garden area is suggested. Work the fertilizer thoroughly into the soil about two weeks before planting time.

A liquid starter fertilizer applied to the transplants at time of planting will help establishment. Apply a half pint of a 20-20-20 or similar solution to each plant, preparing the fertilizer according to label directions.

Planting Suggestions:

All cole crops are frost tolerant. Broccoli transplants may be set out in the garden as early as April 1. For a fall cauliflower crop, set out transplants on July 1.

Broccoli may be spaced 18 inches apart in the row with 24 inches between rows. Cauliflower plants should be placed 24 inches apart in the row with 30 inches between rows.

As cauliflower plants begin to mature and the head, or curd, starts to form, gather together and tie the leaves over the curd with soft twine or tape. This "blanching" is required to ensure that the curd will be white and tender at harvest. There are some 'self-blanching' types available where the leaves curl naturally over the head when grown in cool weather (some tying of the leaves may still be necessary, however).

An even moisture supply is needed for transplants to become established and to produce good heads. As mentioned earlier, an organic mulch will help keep soils cool and moist and suppress weed growth. Hand-pull or use shallow cultivation if additional weed control becomes necessary. Apply 1 to 1.5 inches of water per week if an equal amount of rainfall does not occur. An additional side dressing of a nitrogen fertilizer when the plants are well established may be desirable.

Insect & Disease Problems:

Principle insect and disease problems are the cabbage looper, imported cabbage worm, cabbage maggot, aphids, flea beetles, blackleg, black rot, clubroot, and yellows. See GreenShare Factsheets on specific pests or diseases for information about cultural control recommendations.

Harvesting and Handling:

Harvest the center green flower bud cluster of broccoli while the buds are still tight and before any yellow petals begin to show. Cut the central stem five to six inches below the head. Many cultivars will continue producing bonus side shoots as long as a few leaves are left on the plant, extending the harvest period for a month or more.

The cauliflower curd, like the broccoli head, is actually a group of tightly clustered white or purple flower buds. Harvest the curd when it reaches the desired size but before the buds begin to separate, about two months after transplanting. Cut the head so that at least two wrapper leaves are present.

Adapted from Marianne Riofrio, Ohio State University Extension, 2000