Leeks are extremely hardy, do not take up much space, are easily grown, and resistant to disease of all kinds. A delicious addition to soups or stews. Requires well manured or composted soil.
They are a true biennial, are eaten for both their small bulbs and also for their sheath of flat leaves, mistakenly called a stem.
Start leeks from seed in mid to late winter, or in early spring. The common advice is to plant out leeks when they are 6-8 inches high and perhaps 3/8 inches thick. Knott, in his Handbook for Vegetable Growers, recommends planting out leeks in June or July when they are 1-2 inches in diameter! Whether or not to blanch your leeks is a matter of preference (tender, mild flavor). Green leaves will be higher in vitamin A!
Leeks don't mind being transplanted several times if needed. Seedlings can be placed in 6 inch deep holes and allowed to fill in naturally over the season, which effectively blanches the lower leaves; or they can be planted so that just the bulb of the leek is buried and the plant stands erect. In the Grow Biointensive system, leeks are planted on 6" centers.
Leek cultivars vary in winter hardiness - so check your variety and know your seasons.
Harvest just before the freezing weather unless the varieties you plant can overwinter. Loosen the soil around the plants if necessary to facilitate harvesting them without breakage.
Store the leeks unwashed. Any soil around the roots will help to keep them from wilting. Stored in bunches, with the roots grouped together and occasionally moistened, in a cold (32F) location, leeks will keep for 2-3 months. Another method is to pack them or "heel" them in soil in a root cellar.