Children collecting leaves of red Russian kale (Brassica napus L. subsp. napus var. pabularia (DC.) Alef.) in a family vegetable garden
Kale originated in the eastern Mediterranean and Asia Minor, where it was cultivated for food beginning by 2000 BC at the latest. Curly-leaved varieties of cabbage already existed along with flat-leaved varieties in Greece in the 4th century BC. These forms, which were referred to by the Romans as Sabellian kale, are considered to be the ancestors of modern kales.
The earliest record of cabbages in western Europe is of hard-heading cabbage in the 13th century. Records in 14th-century England distinguish between hard-heading cabbage and loose-leaf kale.
Russian kale was introduced into Canada, and then into the United States, by Russian traders in the 19th century.USDAbotanistDavid Fairchild is credited with introducing kale (and many other crops) to Americans, having brought it back from Croatia, although Fairchild himself disliked cabbages, including kale. At the time, kale was widely grown in Croatia mostly because it was easy to grow and inexpensive, and could desalinate soil. For most of the twentieth century, kale was primarily used in the United States for decorative purposes; it became more popular as an edible vegetable in the 1990s due to its nutritional value.
During World War II, the cultivation of kale (and other vegetables) in the U.K. was encouraged by the Dig for Victory campaign. The vegetable was easy to grow and provided important nutrients missing from a diet because of rationing.
Kale is usually an annual plant grown from seed with a wide range of germination temperatures. It is hardy and thrives in wintertime, and can survive in temperatures as low as -15° Celsius. Kale can become sweeter after a heavy frost.
One may differentiate between kale varieties according to the low, intermediate, or high length of the stem, along with the variety of leaf types. The leaf colours range from light green to green, to dark green and violet-green, to violet-brown.
Classification by leaf type:
Curly-leaf (Scots kale, blue curled kale)
Bumpy-leaf (black cabbage, better known by its Italian translation 'cavolo nero', and also known as Tuscan Cabbage, Tuscan Kale, lacinato and dinosaur kale)
Plain-leaf (flat-leaf types like red Russian and white Russian kale)
Leaf and spear, or feathery-type leaf (a cross between curly- and plain-leaf)
Ornamental (less palatable and tougher leaves)
Ornamental kale in white and lavender
Because kale can grow well into winter, one variety of rape kale is called "hungry gap" after the period in winter in traditional agriculture when little else could be harvested. An extra-tall variety is known as Jersey kale or cow cabbage.Kai-lan or Chinese kale is a cultivar often used in Chinese cuisine. In Portugal, the bumpy-leaved kale is mostly called "couve galega" (Galician kale or Portuguese Cabbage).
Many varieties of kale and cabbage are grown mainly for ornamental leaves that are brilliant white, red, pink, lavender, blue or violet in the interior of the rosette. The different types of ornamental kale are peacock kale, coral prince, kamone coral queen, color up kale and chidori kale.Ornamental kale is as edible as any other variety, but potentially not as palatable. Kale leaves are increasingly used as an ingredient for vegetable bouquets and wedding bouquets.
A traditional Portuguese soup, caldo verde, combines pureed potatoes, diced kale, olive oil and salt. Additional ingredients can include broth and sliced, cooked spicy sausage.
In Scotland, kale provided such a base for a traditional diet that the word in some Scots dialects is synonymous with food. To be "off one's kail" is to feel too ill to eat.
In Ireland, kale is mixed with mashed potatoes to make the traditional dish colcannon. It is popular on Halloween, when it may be served with sausages.
The Kailyard school of Scottish writers, which included J. M. Barrie (creator of Peter Pan), consisted of authors who wrote about traditional rural Scottish life (kailyard = 'kale field'). In Cuthbertson's book Autumn in Kyle and the charm of Cunninghame, he states that Kilmaurs in East Ayrshire was famous for its kale, which was an important foodstuff. A story is told in which a neighbouring village offered to pay a generous price for some kale seeds, an offer too good to turn down. The locals agreed, but a gentle roasting on a shovel over a coal fire ensured that the seeds never germinated.
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