Major commercial varieties include Pinola, Titan, Arkansas, Derik, Palino and Unique. All share the characteristic thick white stem and medium-to blue-green leaves.
An excellent source of Vitamin C as well as iron and fibre. 1 cup (250 mL) of raw chopped leeks contains 57 calories.
Leeks are associated with Wales. This began in 640 AD when Welsh soldiers wore pieces of leek in their helmets to distinguish themselves from their Saxon foes in battle.
Even today the leek is worn as the national "flower" of Wales on St. David's day.
The vegetable has a much longer history. Leeks date back to the early Bronze Age, around 4000 BC. It is said they were part of the diet of those who built the Egyptian pyramids. And Hippocrates, the father of medicine, prescribed the leek as a cure for nosebleeds.
Buying and storing
Good quality leeks are firm and smooth and free of blemishes, with leaves unfaded. Rounded bulb bottoms may indicate old age - look for flat bottoms. A bunch should be bound in several places to prevent leaf damage.
Before storing, trim any bruised or damaged leaves. Keep damp, loosely wrapped, for up to one week at 32°F (0°C) in the refrigerator.
Trim roots and any wilted green ends; remove the toughest outer layer.
Chop or slice and rinse thoroughly in cold running water to remove any grit or sand.
Leeks are ideal in sauces, dressed vegetable dishes, soups, casseroles and stir-fries. Along with potatoes, they're the key ingredients in the classic chilled soup, vichyssoise.
Many other leek-based dishes can be found in the cuisines of Britain, northern Europe and the Middle East.