Kale

Kale does not have a simple wild native range of its own. It is a domesticated leafy form of Brassica oleracea, the species that also produced cabbage, broccoli, cauliflower, Brussels sprouts, and kohlrabi. Its ancestors are associated with wild cabbage populations growing along rocky European coasts, although botanists continue to debate exactly which populations contributed to the cultivated crop.

Early farmers selected these cabbages for large, edible leaves rather than compact heads or enlarged flower buds. Leafy, nonheading forms were among the oldest cultivated expressions of the species. Over many generations, selection produced kales with flat, curled, blistered, blue-green, or purple leaves, adapted to different climates and culinary traditions.

Kale became established across Europe, where its tolerance of cool weather made it a valuable autumn and winter vegetable. It developed especially strong traditions in northern Europe, including Britain, Germany, the Netherlands, and Scandinavia. European settlers later carried cultivated kale to North America, where it became a dependable garden and market crop.

Today kale is grown in temperate regions worldwide. California is a major source for the United States fresh market, while farms in Georgia, New Jersey, the Pacific Northwest, and other cool-season production areas also contribute. Its recent global popularity is new, but the crop itself represents one of the oldest branches of the cultivated cabbage family.