Kale or borecole is a form of cabbage [Brassica oleracea Acephala Group], with green or purple leaves, in which the central leaves do not form a head. It is considered to be closer to wild cabbage than most domesticated forms. The species Brassica oleracea contains a wide array of vegetables, including broccoli, cauliflower, collard greens, and brussels sprouts. The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically.
The name borecole most likely originates from the Dutch boerenkool [farmer’s cabbage]. Some varieties can reach a height of six or seven feet; others are compact and symmetrical and of good quality for eating. Many, however, are coarse, possess an undesirable coloring, and are unappealing and indigestible. Most kale are either annuals or biennials, and are raised from seeds, which, in size, form, and color, resemble those of the cabbage.
These ornamental Kale plants are very showy, and come in a variety of colors, ranging from white to pinks, purples or reds. Ornamental Cabbages and Kales look much the same as their edible cousins, but the ruffled foliage is much fancier and more colorful.