Cabbage, Broccoli, and Other Cole Crops

Cole crops are in the Brassicaceae family, formerly called Cruciferae, and many are in the species Brassica oleracea. A kale-like ancestor was grown in gardens as far back as the time of the Roman Empire. In Europe, cabbage gardens were very impo rtant food sources during the Middle Ages. Differences in morphology between cole crops are undoubtedly the result of early selection for various edible parts. This selection was made easier by the reproductive biology of cole crops.

All cole crops are interfertile (i.e., they can be crossed) and many are self-incompatible (i.e., flowers cannot be fertilized by pollen from the same plant). These characteristics have made it easy to select for new types of cole crops. Self-incompatibility also makes hybrid seed production economical.

Because of their vigorous growth, uniformity of maturation and disease resistances, hybrids are preferred by most growers over the older open-pollinated cultivars.

Plant Characteristics

Cole crops grow best in cool weather. In Alaska, cabbages can grow to 68 pounds with 5-foot diameters! Cabbage plants can continue to grow at temperatures as low as 41 degrees F but little growth occurs over 77 degrees F.

Cabbage, kale, collards and kohlrabi are biennials, flowering only after a period of prolonged cold weather. Cauliflower and broccoli have been selected to bloom as annuals and require less chilling to flower, but they will head sooner in cold weather.

Cabbage stems are unbranched and grow upward very little before expanding in diameter without further growth in length. The first leaves unfold normally to form what is called the frame. Leaves produced later only unfold partially. The inner leaves are then enclosed and can't expand. They will form a solid head as they develop, but if the plants grow too rapidly, or produce a flower stalk, the pressure of the inner leaves against the outer can split the head wide open.

The plant parts eaten differ between the various cole crops more than in any other group of vegetables. In kale and cabbage, leaves are eaten; in broccoli, the green buds and fleshy flower stalks; in cauliflower, the thick flower stalks making up the round, white head or curd; in Brussels sprouts, the axillary bud; in kohlrabi; the swollen leaf base.

Location of Production

The cole crops of cabbage, kale, collards, turnips, rutabaga, Brussels sprouts, broccoli and cauliflower, are among the most widely grown vegetables in the temperate zone. Cole crops are also widely grown during the cool season in tropical and subtropical areas. In 1989, 60 percent of the frozen broccoli and 46 percent of the frozen cauliflower consumed in the United States was imported.

The top cabbage-producing states in 1992 by acreage were New York, Texas, California, Wisconsin, and Florida. The top broccoli producing states in 1992 were California, Arizona, and Texas. Top states in cauliflower production were California, Arizona, Oregon, and New York.

• PRODUCTION PRACTICES: CABBAGE
• PRODUCTION PRACTICES: BROCCOLI
• PRODUCTION PRACTICES: LEAFY GREENS
• PRODUCTION PRACTICES. CAULIFLOWER

In the southern United States, insects tend to be a greater problem in fall cole crops. The main insect pests of cabbage in Georgia in 1987 were the cabbageworm complex, aphids, and the seedcorn maggot. The main pests of leafy greens were cabbageworms, aphids and false chinch bug/stinkbug.

REFERENCES

• Vegetables and specialties: Situation and outlook report (1987-1993). USDA Economic Research Service, quarterly.

• U.S. Dept. of Commerce, Bureau of the Census. 1992 Census of Agriculture. Vegetables, Sweet corn and melons harvested for sale. 1992 and 1987. p. 396-421.

• USDA Agricultural statistics (1947-1993), US GAO, and Vegetables & Specialties: Situation and outlook report (1987-1993). USDA Economic Research Service, quarterly.

• Poleman, C.M., and N.J. Peckenpaugh. 1991. Nutrition essentials and diet therapy. W.B. Saunders Co.

• Boudreaux, J.E., D.K. Pollet, and H.K. Whitam. 1990. Cabbage production in Louisiana. LA Cooperative Extension Pub. 2361.

• Parnes, R. 1990. Fertile soil, a grower's guide to organic and inorganic fertilizers. AgAccess, Davis, CA.

• Miller, C.H., W.E. Splinter and F.S. Wright. 1969. Effects of cultural practices on suitability of cabbage for once-over harvest. J. Am. Soc. Hort. Sci. 94:67-69.

• Konsler, T.R. 1981. Broccoli production for western North Carolina. NC Cooperative Extension Service Horticultural Information Leaflet 5-B, NCSU, Raleigh, NC.

• Hochmuth, G. 1993. Hard figures for petiole sap testing. American Vegetable Grower 41(12):62-63.

• Caldwell, J.S., R.D. Morse and C.R. O'Dell. 1984. Plant spacing for maximum profits- fall broccoli. The Vegetable Grower News, March/April. VPI&SU, Blacksburg, VA.

• IPM Manual Group. 1985. IPM for cole crops and lettuce. Univ. of CA Publication 3307.

• Thompson, H.C., and W.C. Kelly. 1957. Vegetable crops. McGraw-Hill Book Co., 611 p.

• Sanders, D.C. 1990. Cauliflower. NC Cooperative Extension Service Horticultural Information Leaflet 10, NCSU, Raleigh, NC.

• Pierce, L.C. 1987. Vegetables: Characteristics, production, and marketing. John Wiley & Sons, 433 p.

• Sanders, D.C. 1990. Collards. N.C. Cooperative Extension Service Horticultural Information Leaflet 12, NCSU, Raleigh, NC.

• Sherf, A. and A.A. MacNab. 1986. Vegetable diseases and their control. 2nd ed. Wiley & Sons. NY. 728p.

• Douce, G.K., and R.M. McPherson. 1988. Summary of losses from insect damage and costs of control in Georgia, 1987. Georgia Agricultural Experiment Station Special Publications 54.

• Seed catalogs such as Johnny's, Petoseed and Asgrow, NC Extension publications, including the Suggested Vegetable Varieties for the North Carolina Commercial Grower, 1991.

• Rutgers Univ. 1984. Commercial vegetable production recommendations. Bulletin E-001, Rutgers Univ. Cook College, New Brunswick. NJ.

Move directly to: Table of Contents
Last Modified:Thursday, October 4, 2001