Growing Leeks From Seed
Seeds ‘n Such lists “Large American Flag” leek seeds as a new offering in the 2016 catalog, and we urge you to try this European favorite vegetable in your garden this year. But order soon as these seeds need a four-month (120 days) growing season to reach maturity.
Leeks like a bright, airy site on deep, fairly rich, loamy soil with good drainage. Dig in some mature compost just before planting. For early leeks, sow in a cold frame in midwinter, harden off and transplant during mid-spring to harvest in early fall. For a winter harvest, sow leek seeds outside in mid to late spring for transplanting to the garden by mid-summer at the latest.
Leeks are always sown first as seeds, then transplanted as 6-inch seedlings to allow the process of heeling up soil gradually around the stems to blanch them. Transplant by dropping the leeks into holes made with a dibble in furrows 6 inches deep. Cover the roots with soil by watering them in, preferably with compost tea.