Kale, or Borecole, a hardy leafy plant grown primarily as a vegetable and forage crop. Kale has a high nutritive value with appreciable amounts of the vitamins A and C and the mineral calcium. There are several types of kale, ranging in height from less than two feet (60 cm) to nine feet (270 cm). Among the types cultivated are curly kale and Scotch kale, both of which have deeply crinkled leaves, and collards, with somewhat smoother leaves.
Kale is a cool-season plant that is improved in quality by exposure to frost. It is planted in fall and harvested in spring in the South. In the North it is planted in spring and harvested in late fall. Insect pests include aphids and cabbage worms.
Kale is Brassica oleracea acephala of the mustard family, Cruciferae. It is descended from the wild cabbage, Brassica oleracea.