Find out how to grow kale as a cool-season vegetable in fall or spring. Peter Krumhardt Kale (Brassica oleracea) is a popular vegetable for salads, fresh-blended smoothies, and soups. Whether you cook kale or eat it raw, this cool-weather vegetable tastes similar to cabbage. However, its loose, upright, wavy-edged leaves don’t form a head like cabbage. Although kale is classified as a biennial,...