Growing Leeks

With a more delicate and sweeter flavor than onions, leeks add a subtle touch to recipes without overpowering the other flavors that are present. Although leeks are available throughout the year they are in season from the fall through the early part of spring when they are at their best.

Leeks are related to onions, shallots and scallions to which they bear a resemblance. They look like large scallions having a very small bulb and a long white cylindrical stalk of superimposed layers that flows into green, tightly wrapped, flat leaves.

 Leeks have been cultivated since at least 3000 BC, and they are native to the broad region stretching from Israel to India. Relished throughout Europe. They have been cultivated for so long that their beginnings are uncertain.

Most leeks require a long growing season of about 120-150 days and need a minimum of eight hours of bright sunlight daily. They prefer a slightly acid soil, with a pH of 6.0-6.8, but will grow well in even a slightly alkaline soil.

In northern climates, start leeks inside in late February or March. For best results, transplants should be no more than 10-15 weeks old when set out in the garden. Harden off the plants for 5-7 days before transplanting by putting them in a cold frame. If you don't have a cold frame, set them outside for longer periods each day while returning them to the shelter of your home or garage at night.

Transplant leeks as soon as early spring weather has stabilized and daytime temperatures are at least 45 F (7 C) Plant them 2-6 in.(5 to 15 cm) apart with 12-36 in.(30 to 95 cm) between rows. Trim the roots on the transplants to 1 in.(2.5 cm) to facilitate transplanting, if necessary.

Leek leaves consistently emerge opposite each other, directly above the previous leaf. Two in.(5 cm) spacing works well if plants are set out so the leaves are parallel to each other, like rungs on a ladder. This will keep the leaves from growing into each other plus make the best use of space, light and air circulation.

For long white stems, plant leeks in furrows or hill them. Set transplants at the bottom of a furrow, 5-6 in.(12 to 15 cm) deep. As the plants develop, raise the soil level along the stems up to the leaves, gradually filling the furrow. Or, hill leeks by adding compost or similar mulch material around the plants several times during the growing season.

A transplant solution of half strength 20-20-20 or 10-10-10 fertilizer will get them off to a good start. Mid-summer, side dress with a balanced fertilizer such as 10-10-10 at a rate of one cup per 10 ft.( 3 m) row.

Leek roots are fiberous and shallow so take care not to damage them by hoeing close to the plant.

Water leeks thoroughly every week. Excess moisture promotes fungal disease.

HARVEST

Harvest leeks by either gently twisting and pulling them from the earth or digging and lifting them. The tops are entirely edible but since the leaves can be quite long, trim them to a more manageable length at harvest, if desired.

Leeks are fairly frost tolerant, so you can delay harvest until after the first few light frosts. Because they're biennial, they won't set seed until the second year. However, they may not over-winter well in our climate (USDA zones 3 and 4) without a protective mulch.

VARIETIES TO GROW