University of Maryland Extension: Plant of the Week
Leek
Allium ampeloprasum
Text by Bob Orazi
For a vegetable that deer won’t eat and few diseases or insects bother, plant leeks.
A member of the onion family, leeks are considered a gourmet vegetable for soups, casseroles and other dishes desiring a mild onion flavor. They are a long season crop, needing 120 days to reach maturity. For this reason, start them indoors in February or early March. They also can be direct seeded in early spring, but this extends their maturity date 30 days.
Leeks prefer soil with a pH of 6.0 to 6.8, rich in organic matter. Transplant the young seedlings into a 6” deep furrow, spacing 4”to to 6” apart. Clip the fibrous root system with scissors to make handling easier.
To avoid planting the seedling too deep, use a gentle stream of water to wash soil over the root system. As the plants grow, gradually fill the furrow with soil to blanch the stem. The stem’s white portion is its edible part.
Fertilize with a starter solution at half strength at planting time. In midsummer, side dress with a complete fertilizer at one cup per 10-foot row. Harvest leeks when the white fleshy part of the stem gets about 1” in diameter. Leeks tolerate frost and cold temperatures, so harvest can continue well into the fall. If mulched with a thick layer of chopped leaves, leeks will resume growth in the spring, extending harvest even further.
