Planting and Harvesting Your Leeks

UPON RECEIPT. You have received live plants that should be planted as soon as possible. If you are unable to plant them right away, remove them from the box and put them in a cool, dry area. The roots and tops may begin to dry out, but the plants will be fine for approximately 2 weeks, living off their stored energy. After planting, the leeks will make new roots.

PREPARING THE SOIL. Leeks, like onions, are best grown in a fertile and well-drained soil with a good balance of nutrients. Organic gardeners should work in rich, finished compost. Spread lime if your soil is too acidic (pH under 6.0). If you use commercial fertilizer (we recommend 10-20-10), distribute 1/2-cup of fertilizer per 10 linear feet of row and dig thoroughly into the top 4-6 inches of soil.

PLANTING. Set plants out approximately 6 inches deep and 6 inches apart. Take a handle of the hoe or a broom-stick and poke holes 6-8 inches deep where each plant will go; then place the plants, one to each hole, so the youngest leaves protrude just above the soil surface. Use a sprinkler or fine hose to water plants in. This will settle the soil in the holes around the roots at the bottom and provide automatic 'blanching' (See below) for the lower part of the stems. Alternatively, use a hoe to dig a narrow trench about 8 inches deep. Set the leeks in the trench and space them about 6 inches apart. Fill the trench with soil and press firmly but gently into place.

BLANCHING. Planting leeks deep in the soil "blanches" them: the part of the stem below the point where the leaves fan outwards (called the shank) is deprived of sun, keeping it white, tender and more flavorful. As the plants grow, mound more soil around the stems gradually, about every two weeks, until the plants reach their full height.

FERTILIZING. Leeks require a lot of nitrogen. Give plants a supplemental feeding of liquid fish emulsion or other fertilizer about 3 weeks after planting; continue to fertilize every 3-4 weeks thereafter. If you use a dry granular fertilizer, water it in well.

WATERING. Throughout the growing season keep the soil evenly moist. Leeks that suffer from a lack of moisture grow unevenly, developing a strong flavor and pithy texture.

WEED CONTROL. It is important to control weeds around leek plants. Start hand-weeding or hoeing as soon as weeds begin to appear. Be careful not to damage the young leek plants. Keep the soil loose and mound the dirt up around the plants regularly, as high as where the leaves fan outwards, in order to blanch the stems for better flavor. A light organic mulch will help to control weeds and preserve moisture.

DISEASE AND INSECT CONTROL. You can generally expect a disease-and-insect-free crop, but leeks do occasionally have problems similar to those afflicting onions. They can be susceptible to two major diseases: blight and purple blotch. If the leaves turn pale-green then yellow, blight has probably affected the plant. Purple blotch causes purple lesions on the leaves. Heavy dew and foggy weather favor the spread of both blight and purple blotch, and when prolonged rainy spells occur in warm weather, these diseases can be very destructive. The best cure is prevention: plant in well-drained soil, run the rows in the same direction as prevailing winds (the direction from which the wind blows most commonly during the growing season), and avoid planting near windbreaks that will prevent good air circulation around the leek foliage. If conditions favoring these diseases persist, spray a fungicide labeled for use on onions and leeks, carefully following the instructions.

The most destructive insect is the onion thrips. Thrips are light brown in color and are less than 1/16in. long. They feed by rasping the surface of the leaves and sucking the juices, causing deformed plants with silvery blotches. Thrips overwinter in weeds, so keeping the garden clean can help reduce their population. Combat serious infestations by using insecticidal soap.

HARVESTING AND STORAGE. 'Lancelot' Leeks are an early variety, maturing about 70 days from planting out, but they can be harvested at any time before that for use as a mild flavored alternative to scallions or chives. Unlike Onions, leeks do not need a rest period before harvest and are best when harvested fresh from the garden, as they don't store well--up to a week in the refrigerator, if kept moist. To harvest the leeks when mature, loosen the soil gently with a garden fork and pull the plants from the ground, being careful to shake off most of the dirt. If you're not going to use them right away it's best to cut off the top leaves in a V shape (with the outside leaves shortest) which will neaten their appearance and stop the plants from withering or drying out too quickly.