ABOUT THE PLANT
Description: The leek resembles a large green onion, or scallion, long and cylindrical, but the flavor is milder and slightly sweeter. It does not form a bulb, but rather a thick, fleshy stalk about the same diameter as the base, and the leaves are flattened into a fanlike sheaf. The ”bulbs”, or stalks are white, transitioning to light green, then very dark green/blue-green at the tops. The whole plant reaches upward of 2-3 feet.
Origin: Native to eastern Mediterranean lands and the Middle East.
Usage: The most edible parts of leeks are the white and light green parts of the stalks. They are more tender and have the most flavor. Leeks are used to enhance the flavor of soups and casseroles. They are used as a side dish by gently sauteing. Fresh, raw leeks are used in salads, dips, and some sauces. Leeks are delicious as a filling in tarts and pastries.
Interesting facts: In 1984, British authorities featured a Leek on the reverse side of the British pound coin, which represented the Welsh part of the United Kingdom.
HOW TO GROW
General requirements: Leeks grow best in loose, well-drained soil with a pH between 6.0 and 7.0. They prefer cooler weather between 55°F-75°F. Enrich with high organic matter such as well-rotted manure or compost in spring or fall. Keep plants well-watered, but not soggy. Side-dress with a balanced fertilizer such as 10-10-10 in mid-summer. Leeks require a growing season of about 4-5 months and a minimum of eight hours of sunlight daily. You can hill the plants by planting them at normal soil level, then adding compost or soil around and up the plants several times during the growing season. This method will increase the white portion of the “bulb” by blocking sunlight and therefore chlorophyll production. Another method is to plant leeks in furrows. Plant them at the bottom of a six-inch deep furrow. As the plants grow, add soil to the furrow, gradually raising the soil level.
In the garden: Direct seed outside 2 weeks before the last frost date. Sow seeds 1/4 inch deep and 2-3 inches apart with rows spaced 12 inches apart. Thin seedlings to 6 inches apart.
In containers: Use a deep container (18 inches or so) that has good drainage. Place in full sun. Fill it about 2/3 full of soil to begin with. Sow seeds ¼" deep and at least 2 “ apart, but the less space you give them, the smaller they will grow. As the seedlings grow, continue adding more soil so that they will blanch. Make sure to water and fertilize regularly. Use liquid plant food such as fish emulsion or compost tea.
Transplanting: Start seeds indoors 8-10 weeks before the last frost date. Scatter seeds about 1 inch apart into flats filled with potting soil and cover them with a light dusting of more potting soil. Place flats in a warm, well-lit area. The ideal soil temperature for leek seeds to sprout is around 70°F. You may need to use a seedling heat mat and grow lights to ensure 8 or more hours of light. Gently water. After seedlings emerge, remove the heat mat. Keep the potting soil moist as the seeds germinate. Once the leek seedlings are at least 7 to 8 inches tall and about as thick as a pencil, it’s time to plant your leeks outside. Harden off the plants for five to seven days before transplanting. To do this, set them outside for a couple of hours, and then longer periods each day while returning them to the shelter at night. Transplant leeks as soon as daytime temperatures are at least 45°F. If necessary, trim the roots of the transplants to one inch to help you transplant. Plant them two to six inches apart, and 12 inches between rows. Use a transplant solution of half-strength 10-10-10 fertilizer to get the plants off to a good start.
Plants: Harvest leeks when they reach a diameter of between ½ to 1-½ inches. Wash your leek plants before cooking with them; as dirt accumulates between their tall leaves. Leek tops do not die back like their onion and shallot cousins. Harvest leeks by pulling them from the earth or digging and lifting them with a garden fork.
Seeds: Leeks are biennials, meaning they flower and produce seeds in the 2nd year. Because leeks are fairly cold hardy, they can overwinter in the garden in many regions. To produce seeds from leeks, select several perfect leeks, and if necessary for your region, store them through winter, ideally, in a cool, dark, dry space. Replant them in early spring. It is recommended to stake leeks to prevent lodging during flowering. To harvest seeds, cut the seed stalk about 6 to 8 inches below the seed head. The harvested seed heads should then be placed in an open container, or on a screen, to continue drying in a well-ventilated space for at least seven days. Place the heads in a paper bag and shake the seeds free. Assure that the seeds are completely dry before storing the seeds in a cool, dry place.
Common name: Leeks
Latin name: Allium ampeloprasum var. porrum
Life cycle: biennial but typically grown and harvested as an annual
USDA Zones: 3-11. In southern regions (7 -11), plants can overwinter in the ground, making them perfect for fall planting. In northerly zones (3-6), plant in early spring, as soon as soil can be worked.
Seeds per ounce: ~9000