Growing Broccoli & Cauliflower

Broccoli Most home gardeners don't realize there are two types of broccoli: heading and sprouting. Most garden broccoli is of the heading types, which is closely related to cauliflower and forms a large central head. When this is removed, side branches will form throughout the summer. Sprouting, or Italian, broccoli, forms may florets or small heads but these do not produce a large solid head.

Cultivars, or cultivated varieties, of broccoli recommended for Nebraska include the following:  

  • 'Green Comet'- 55 days, small heads, freezes well, heat tolerant
  • 'Premium Crop'- 71 days, freezes well, holds long
  • 'Packman'- 57 days, very large heads, excellent side shoots

Broccoli prefers full sun, well-drained soil with high organic matter, and a 6.0-7.5 soil pH level. Broccoli is a hardy, annual plant that prefers cool growing temperatures, 60-65° F. To raise broccoli, buy transplants locally or produce your own and set them out from April 10-30 for an early summer crop, or July 15-30 for a fall crop. Set plants 15-24 inches apart in rows 24-36 inches apart. Sprouting broccoli is sown directly in the garden in spring. Broccoli requires a high level of fertility, which is best provided through slow release or organic fertilizer sources to avoid the development of hollow stems. During soil preparation, work compost or rotted manure into the soil. Use a starter fertilizer when transplanting, and sidedress the plants three weeks after planting with 1 ½ ounces 33-0-0 per 10 foot row.

Broccoli has a relatively shallow, fibrous root system, so cultivate carefully when needed for weed control, then apply an organic mulch. Provide an even amount of moisture to the garden, especially after transplanting and during the maturation of the heads. Moisten the soil at least 6 inches with each application to encourage deeper rooting, but the never let the soil become waterlogged.

The heads of broccoli are really flower buds. These must be harvested before the yellow flowers begin to open. Mature heads normally measure 3-10 inches across. Harvest the heads with 6-8 inches of stalk. The lateral heads that develop later are smaller, but can be harvested continuously through the summer. Eat fresh, or freeze the surplus.

Broccoli can have problems with several insect and disease problems in the garden including cutworms, cabbage looper, imported cabbage worm, flea beetles, aphids, blackleg, blackrot and fusarium wilt. Flea beetles can severely damage small transplants in spring. Control insects before the heads start to develop, or protect the heads with a physical barrier like row covers.

Cauliflower Growing cauliflower in the home garden is similar to growing broccoli, but is complicated by cauliflower's sensitivity to temperature extremes. For example, many gardeners experience buttoning of cauliflower heads in spring, or a failure of the head to gain in size after it reaches about an inch or less in diameter. Buttoning is usually due to transplant stress, heat stress during the head formation period, or spring temperatures that were too low.

Some cauliflower cultivars require a longer growing season for fall production than is possible in colder regions of Nebraska. Use short-season types or season extenders in these areas. Fall planting is recommended in Nebraska because high temperatures in early spring often reduce the quality.

Cultivars recommended for Nebraska include:

  • 'Snow Crown' hybrid- 50 days, early, dependable
  • 'Violet Queen'- 62 days, purple heads look like broccoli
  • 'Alverda'- 60 days, light green curds, "Broccoflower."

Cauliflower prefers full sun, well-drained soil with high organic matter, and a 6-7 soil pH level. It is a hardy, annual plant that prefers cool growing temperatures, 60-65° F. Buy transplants locally or produce your own and set them out from after the danger of frost is past, usually May 15th. For a fall planting, sow seeds in late June or early July. Set plants 15-24 inches apart in rows 24-36 inches apart. Use a starter fertilizer when transplanting, and sidedress the plants three weeks after planting with 1 ½ ounces 33-0-0 per 10 foot row. Cauliflower a shallow, fibrous root system, so cultivate carefully when needed for weed control, then apply an organic mulch. Provide an even amount of moisture to the garden, especially after transplanting and during the maturation of the heads. Moisten the soil at least 6 inches with each application to encourage deeper rooting, but the never let the soil become waterlogged.

Cauliflower should be blanched when the flower head, or curd, is about 2-3 inches wide. Three to four large outer leaves are pulled up over the curd and fastened with a rubber band, or are broken over the top of the cauliflower and tucked in on the other side of the curd. Normal blanching time is 4-8 days, but may take longer in the fall. Self-blanching types, which have leaves that grow up over the head, may eliminate the need for this practice. If weather is warm during the blanching period, tie the leaves loosely to allow air circulation.

Harvest while the curd is still firm, compact, white and fairly smooth; if it gets too mature, it will become grainy or ricey. Cauliflower usually produces only one head per plant. Leave a ruff of leaves at the base of the head when harvesting to prolong keeping quality. Store at 32°F, with 95% relative humidity for 2-4 weeks. Cauliflower can also be frozen for longer storage times.

Cauliflower can have problems with several insect and disease problems in the garden including cutworms, cabbage looper, imported cabbage worm, flea beetles, aphids, blackleg, blackrot and fusarium wilt. Flea beetles can severely damage small transplants in spring. Control insects before the heads start to develop, or protect the heads with a physical barrier like row covers.