Cabbage is a hardy cool-season vegetable and develops best quality when grown under cool, moist conditions. Lettuce seedlings will tolerate a light frost. Temperatures between 45 F and 65 F are ideal.
Sow cabbage seed 1/4 to 1/2 inch deep. Keep the seeds moist and thin or transplant the seedlings to the desired spacing. The plants removed may be transplanted to another row or flat.
Transplant cabbage in early spring so it has time to mature before the heat of summer.
Late fall cabbage must be started during the heat of mid-summer, but it develops its main head during the cooling weather of fall. It may be transplanted or seeded directly in the garden. In summer, if possible, place seed flats or seedbeds where some protection from the sun is available,
Space plants 12 to 24 inches apart in the row, depending upon the variety and the size of head desired. The closer the spacing, the smaller the heads. Early varieties are usually planted 12 inches apart in all directions. Early varieties produce 1 to 3 pound heads and later varieties produce 4 to 8 pound heads
Fertilize when transplanting and side-dress with nitrogen fertilizer when the plants are half grown.
Harvest anytime after the heads form. For highest yield, cut the cabbage heads when they are solid (firm to hand pressure) but before they crack or split. When heads are mature, a sudden heavy rain may cause heads to crack or split wide open. The exposed internal tissue soon becomes unusable. Harvest and salvage split heads as soon as possible after they are discovered.
In addition to harvesting the mature heads of the cabbage planted in the spring, you can harvest a later crop of small heads (cabbage sprouts). These sprouts develop on the stumps of the cut stems. Cut as close to the lower surface of the head as possible, leaving the loose outer leaves intact. Buds that grow in the axils of these leaves (the angle between the base of the leaf and the stem above it) later form sprouts. The sprouts develop to 2 to 4 inches in diameter and should be picked when firm. Continue control of cabbage worms and other pests. If this control cannot be maintained, remove and destroy or compost the stumps, because they serve as a breeding ground for diseases and insect pests.
Store in the refrigerator for weeks. Cover loosely with a plastic bag or use perforated bags. Do not wash cabbage before storing, the extra moisture will hasten deterioration.