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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Harvesting the Cole Crops

This article was published originally on 5/16/2007

Vegetables must be harvested at the proper stage of maturity in order to obtain the highest quality produce. The harvest and storage recommendations for broccoli, cauliflower, cabbage, and other cole crops are listed below.
Broccoli. Broccoli should be harvested when the head is fully developed, but before the small yellow flower buds start to open. At harvest, the terminal head should be tight, blue-green, and approximately 6 to 7 inches in diameter. Several smaller side heads (about 1 to 3 inches across) will develop in the axils of the leaves after the central head is removed.
Broccoli may be placed in a perforated plastic bag and stored in the refrigerator for up to 10 to 14 days.
Brussels Sprouts. Beginning at the base of the plant, harvest the buds (sprouts) when 1 to 1_ inches in diameter. Continue to harvest the sprouts higher up on the plant as they mature. Store the sprouts in a perforated plastic bag in the refrigerator for up to 3 to 5 weeks.
Cabbage. The harvest of cabbage may begin when the heads are firm and the size of a softball. Mature cabbage should be harvested when the head is solid and tight, before they crack or split. Splitting is caused by excessive water uptake; the resulting pressure splits the head. Splitting of mature heads may be prevented by pulling the plant upward and gently twisting. Some of the roots will be broken, thereby reducing water uptake.
Cabbage may be placed in a perforated plastic bag and stored in the refrigerator. A cool, moist (32º, 90 to 95% relative humidity) root cellar would be fine for prolonged storage up to 3 to 4 months.
Cauliflower. Cauliflower heads exposed to sunlight become cream colored and coarse in texture. To obtain high quality cauliflower, the heads must be blanched by loosely tying the outer leaves over the heads when approximately 2 to 3 inches in diameter. The leaves can be tied over the heads with twine or cloth strips. The exclusion of light or blanching will keep the heads white and tender.
Cauliflower should be harvested when the heads are smooth, firm, and compact. Full-sized heads may be 6 to 8 inches across. Overmature heads will begin to open up and become "ricey."
Cauliflower may be placed in perforated plastic bags and stored in the refrigerator for up to 2 to 4 weeks.
Chinese Cabbage. Chinese cabbage is normally harvested when the heads are fully developed. However, plants may be harvested as greens anytime prior to maturity. Once harvested, Chinese cabbage may be stored in a perforated plastic bag in the refrigerator.
Collards. Periodically harvest the larger, lower leaves or cut off the entire plant near ground level. Store in perforated plastic bags in the refrigerator.
Kale. Periodically harvest the older, outside leaves or cut off the entire plant near ground level. Store in perforated plastic bags in the refrigerator.
Kohlrabi. Harvest kohlrabi when the swollen stems are 2 to 3 inches in diameter. Kohlrabi that is larger than 3 inches in diameter is usually tough and woody. To store, remove the leaves and roots and place in the refrigerator.
Rutabaga. Harvest roots when 3 to 5 inches in diameter. The foliage may also be harvested for greens. Prior to storage, trim off the foliage to within 1 inch of the crown with a sharp knife. Also, remove the tap root. Rutabagas should be stored at 32 to 35º with a relative humidity of 90 to 95 percent.
Turnips. Harvest turnips when the roots are 2 to 4 inches in diameter. Roots larger than 4 inches in diameter may be poor tasting and woody. Optimum storage conditions are a temperature of 32º and a relative humidity of 95 percent.

Page References: 
53-54
Year of Publication: 
2007
Issue: 
IC-497(11) -- May 16, 2007