Cabbage or headed cabbage (comprising several cultivars of Brassica oleracea) is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage, B. oleracea var. oleracea, and belongs to the “cole crops” or brassicas, meaning it is closely related to broccoli and cauliflower (var. botrytis); Brussels sprouts (var. gemmifera); and savoy cabbage(var. sabauda).
Cabbage heads generally range from 0.5 to 4 kilograms (1 to 9 lb), and can be green, purple or white. Smooth-leafed, firm-headed green cabbages are the most common. Smooth-leafed purple cabbages and crinkle-leafed savoy cabbages of both colors are rarer. It is a multi-layered vegetable. Under conditions of long sunny days, such as those found at high northern latitudes in summer, cabbages can grow quite large. As of 2012, the heaviest cabbage was 62.71 kilograms (138.25 lb).
Cabbage seedlings have a thin taproot and cordate (heart-shaped) cotyledon. The first leaves produced are ovate (egg-shaped) with a lobed petiole. Plants are 40–60 cm (16–24 in) tall in their first year at the mature vegetative stage, and 1.5–2.0 m (4.9–6.6 ft) tall when flowering in the second year.Heads average between 0.5 and 4 kg (1 and 8 lb), with fast-growing, earlier-maturing varieties producing smaller heads. Most cabbages have thick, alternating leaves, with margins that range from wavy or lobed to highly dissected; some varieties have a waxy bloom on the leaves. Plants have root systems that are fibrous and shallow. About 90 percent of the root mass is in the upper 20–30 cm (8–12 in) of soil; some lateral roots can penetrate up to 2 m (6.6 ft) deep.
In 2014, global production of cabbages (combined with other brassicas) was 71.8 million tonnes, led by China with 47% of the world total (table). Other major producers were India, Russia, and South Korea.
