You should plant leek seeds early to give them adequate time to grow. Leeks are a mild flavored form of onions. Leek plants also are related to garlic, which is scientifically known as the Alliaceae family. You can easily grow leeks by choosing the best time to sow seeds indoors, and the proper way of transplanting them to the proper soil conditions.
Planting and Caring for Leek Seeds Inside
Plant leek seeds inside, five weeks before the final frost. Use a planter flat and fill each slot in the flat with topsoil. Dig a small hole in each slot, 1/2 inch deep. Put a leek seed in each hole in the planter flat. Cover the leek seeds lightly with topsoil and gently pack it down. Use a spray bottle filled with water to keep soil moist but not soggy. Mist each planter flat slot twice a day. Expect leek seeds to germinate a week after sowing.
Transplanting Leek Seedlings Outdoors
Choose a location for leek seedlings that gets full sunlight. Check pH soil conditions for the location you choose and make sure the pH of the site ranges between 6 and 7.5. You can buy soil pH testers at garden centers and home improvement stores. Dig out a trench that is 9 inches deep with a hoe and shovel. Leek plants are generally grown in trenches for adequate growth and transplanted when they are at least 6 inches tall. Gently pull the leek seedlings out of the flats. Loosen the roots of the leek seedlings by gently pulling on them. Trim the roots with scissors to around 3 inches. Place the leek plants 7 inches apart from one another and cover with topsoil. Gently pat down the earth around each leek. Water each plant so that soil is wet but not muddy.
Collect a pointed shovel, several jugs of water, enough bags of topsoil to make a dirt mound for each leek and a bag of fertilizer. Choose a fertilizer that is formulated for vegetables. Make sure that fertilizer numbers are low, such as 1-2-3.
Apply dirt mounds with a pointed shovel around the leek plants. Do this when the leeks have grown for about a month outdoors. Mounding makes the stems of your leeks much sweeter, and the process is called blanching. Lightly pack topsoil around the leek stems, leaving only the leaves of the leek exposed. About 6 inches of the leeks should be buried in the dirt; and it should be the entire stalk of the leek. Water the soil after mounding to make it damp but not waterlogged. Apply the fertilizer, following the directions on the packaging for proper dosage.
Check your leek leaves once a week for orange pustules and remove leaves with rusty spots. Remove weeds weekly around your leek plants to prevent nutrient and water loss. Give leek plants a lot of water during dry summer periods. Water at least twice a week, and keep soil moist. Apply the fertilizer every four weeks after transplanting leeks.
Check the top of your leeks for yellow coloring, 100 to 110 days after transplanting. Remove leek plants from the soil after they have developed yellow tops. Place leeks in the sunshine for a few days to dry.