Leeks are in the Allium family and carry some of the same health benefits as garlic and onions. (See Garlic and Onion entries for the benefits of phytonutrients in this family.) Leeks differ from their family members in giving fewer nutrients per weight. Because they are less concentrated, you must eat more to get the same nutrition. Compared to garlic and onion, this is easy considering how mellow and sweet their taste is. In general, regular eating of veggies in the Allium family is linked with lower bad cholesterol concentrations and preventing or inhibiting the growth or spread of cancer. With a small dose of vitamin C, iron, folate and B6, leeks add a few antioxidants to get rid of dangerous free radicals, help activate hemoglobin molecules for oxygen transport, lower high levels of the compound homocysteine (damages blood vessels at high concentrations), and helps the body metabolize food to provide energy.
Vitamin and Mineral Content
Vitamins – C, B9 (Folate) and B6 (Pyridoxine)
Minerals – Manganese and Iron
With regular eating, leeks team up with other Allium veggies to help reduce the symptoms or prevent development of atherosclerosis, heart disease, prostate and colon cancer, ovarian cancer and many other cancers.
How to Grow
Leeks are great to grow for a winter harvest. They need little attention and are hardy through all but the coldest winters when the soil gets too hard to dig. Choose a site with plenty of sunshine. Work in a generous dose of organic matter in the form of aged compost, manure or planting mix. They prefer a soil pH around 6.5. Add lime to raise, if needed. The pale color we are used to seeing near the bottom of leeks comes from the blanching process during cultivation. There are two ways to do this. First, you can multiple sow them in seed trays in mid-spring. Fill each cell with highly fertile soil (peat and planting mix). Make a small dip in each cell and place 6-7 seeds in each. Cover the seeds with a fine medium such as sand, cover with plastic, water well, and place on a windowsill, under a florescent light or in the greenhouse at or near 60˚F. Once germinated, remove the plastic. When they reach 1-2 inches, they are ready to plant out (around early summer). Plant them about 10 inches apart in rows spaced 10 inches apart. Stagger the rows this way to prevent overcrowding. For an alternative technique that blanches each plant, sow seeds 6 inches apart outdoors in a shallow drill in mid-to-late spring. When they reach a couple inches tall, transplant them into pre-made dibber holes 6-8 inches deep. Place one plant per hole and space the holes out by 6 inches. Space rows out by 1 foot. Don’t fill the hole with soil. Instead, water each hole a little after placing the leek to get some soil over the roots. As they grow, keep the area weed free by hoeing. Also, to keep the blanch going, push some soil up around the base throughout the growing season. Leeks are ready to harvest in mid-fall. They can be left in the ground until needed unless the weather will make the soil too hard to dig them up. In that case, dig them up early and store in a moist peat soil.
Leeks are usually pest free. If you have problems, consult your local nursery.
Companion plant leeks next to carrots and celery since they repel carrot fly. Do not plant next to beans, peas or parsley.