Leeks date back to the time of the Ancient Egyptians with this particular variety originating around 1870. Leeks create a tasty pearl white bulb with huge green leaves and have a delicate onion flavor. They are a favorite ingredient in soups, stews and salads. A very hardy vegetable, it overwinters well in most regions doing well in both southern and northern states.
Leeks are easy to grow. They require little to no attention and are generally pest-free. In the kitchen, they can be substituted for onions and, unlike onions, can be chopped and frozen for use in the winter after you run out of your own onions. Early leeks reach full size in 50 to 75 days, though some hardy types take 100 days or more. Prepare the soil for leeks by lightening it up with lots of compost. There's no need for much fertilizer. Grocery store leeks have long white stems because the stems have been buried in soil or sand to prevent light from turning them green. You can do this, too. The reward is longer, more usable stems. This process is called blanching. To blanch leeks in your garden, plant each seedling at the bottom of a hole that's about 6" deep. Fill in around the base of the leek as it gradually gets taller. By the end of the season, the bottom of each plant will have a 6-8" section that's tender and white.
Choose a weed-free, well-drained location. Raised beds are ideal. Leeks are good for intercropping with other garden plants, especially early-maturing spring greens. Do not plant where other onion family crops have been grown in the past 3 years.
You can direct-seed leeks, or start transplants indoors. Long-season varieties are best started indoors.
Start transplants about 8 to 10 weeks before last frost date. Sow seeds in flats about ¼ inch apart and ½ inch deep. Transplant to cell-type containers when they are about 2 inches tall. If you skip this step and continue growing in open flats, simply tease apart and trim roots when transplanting into the garden.
Around the average last day of frost, set hardened-off transplants 4 to 8 inches deep, 4 to 6 inches apart, in rows 20 inches apart. Deep planting reduces need for hilling to blanch the base of the plants. Transplants should be about 6 to 12 inches tall - the bigger, the better. Only a few inches of leaf need to show above the soil.
Direct seed about 4 weeks before average last frost ½ inch deep, 1 inch apart, in rows 20 inches apart. Thin to 4 to 6 inches apart.
Hill or mound soil around stems several times to blanch as leeks grow. (A single large hilling while plants are young can cause them to rot.) Or, place a portion of cardboard paper towel center around the lower part of the stem. Leeks have shallow root systems and need consistent moisture and good weed control. Water weekly if weather is dry, and mulch to retain moisture and suppress weeds.
Most of the general information provided is from the Vegetable Encyclopedia at www.gardeners.com, with additional facts provided by your friends at Seattle Seed Company.