Brassica oleracea, Acephala group
Frost sweetens the taste of this vitamin- and mineral-packed cooking green. Kale can thrive in semishade and in cloudy climates; hot weather turns it tough and bitter. Some varieties have very curly, frilly leaves; others are smoother. ‘Red Russian’ is one variety that has leaves that develop a magenta hue after frost.
Planting: Rich soil promotes a faster-growing and more tender crop. Where summers are cool, sow seeds in early spring, ½ inch deep in rows 2½ feet apart. For a fall-winter crop, sow seeds or set out transplants at least 6 weeks before the first frost; rake to cover seeds.
Growing guidelines: Thin plants to 2 feet apart. Keep the soil moist. Mulch established plants to control weeds.
Problems: See the Cabbage entry for insect and disease controls.
Harvesting: Harvest outer leaves as needed; use young tender leaves for salads and older leaves for cooking.