Like all brassicas cabbages are descended from sea cabbages (still found wild on European coasts), so can manage with little fresh water and are adapted to store any they get - which makes them succulent. They are also biennial, storing food from their first year's growth before flowering the second year - which means this is available to us all winter.
Thanks to a great range of cultivars cabbages can be eaten fresh all year round. There are two basic types: ones which form a head (round or conical), and ones which don't (loose-leaved). Hard-headed varieties keep for up to 2 weeks in a fridge, loose-leaved up to a week. SPRING CABBAGES are loose-leaved (but SPRING GREENS are a hearting type picked when immature, before the heart has formed). SAVOY cabbages are the hardiest - with their mild flavour and crisp texture they can be eaten raw in salads, or cooked. RED cabbages, needing an extra-long growing season, can be stored for winter, and like Savoy, and Chinese cabbage, eaten raw or cooked. CHINESE cabbage, grown in the Far East since the 5th century, unknown in Europe until about 1900, also comes in hard- and loose-headed varieties. The loose-headed variety is known as pak choi, the hard-headed as Chinese leaves (or pe-tsai, or peking cabbage).
Health and nutrition
Lightly steamed or boiled, cabbage is very good for you! The ancient Greeks and Romans (including Pythagoras and Cato the Elder) praised it for promoting health and long life, and in folk medicine it's long been seen as a cure-all - a reputation to some extent confirmed by modern medical research. It was important in combating scurvy before citrus fruits were known for this, as it's a good source of vitamin C, as well as vitamins E, K, B1 (thiamine) and B2 (riboflavin), and minerals and trace elements. Currently it's thought to be a source of phytochemical substances that help protect against cancer.
Wild cabbage was known to the ancient Britons, and the Romans brought garden varieties here - probably less bitter, loose-leaved types. Around the 1570s the first Savoy cabbages were introduced here from Holland, probably at the same time as smooth, hard-packed winter white cabbages, still known today as DUTCH.
In parts of Europe there have been times when cabbage was pretty much the only vegetable available, so it plays an important role in many national cuisines. Cabbage soup is a favourite peasant dish in Southern France, Central and Eastern Europe; sauerkraut (cabbage stored in salt and left to ferment) is a German/Austrian variation on their numerous national cabbage dishes, and a way of preserving cabbage through winter; in Ireland colcannon is a national dish. We don't have quite such a warm traditional relationship with cabbage in Britain, where many of us still associate it with the sulphurous smell of overboiled, institutional vegetables. Cabbage really doesn't deserve this reputation, which can be counteracted just by making sure it's cooked briefly.