Leeks will not form bulbs or produce cloves like their cousins, but instead develop an edible, 6 – 10 inch-long, round stem that can measure 2 inches in diameter. The leek’s cylindrical, white, edible root gradually becomes a stalk with a fan of dark green, flat leaves. Offering an earthy, mild onion flavor, the texture of a leek is crunchy when raw and silky when cooked. Leeks are considered to be the sweetest and most mild members of the onion family. Leeks will stay in the ground through October into November.
Set plants 6–12″ apart in trenches in well-dug beds with generous quantities of organic matter. Avoid transplanting next to grass strips; slugs love to dine on tiny allium seedlings. Irrigate seedlings whenever the topsoil dries out.