A relative of the onion, leeks are more mildly flavored and rarely form bulbs. Rather, it's the bottom 6" of white stem that is edible. Because of its long growing season, many customers will choose to grow leeks from transplants that can be planted in the garden starting in early spring. Space plants 6" apart with 18" between rows and bury stems so soil reaches the base of the green leaves. Leeks prefer full sun and sandy, well-drained, slightly acidic soil, amended with organic matter. Because of their shallow root system, water leeks frequently, and take care when weeding or cultivating around plants. Mulching is recommended to retain soil moisture and to keep weeds down. Although not heavy feeders, they will benefit from an application of a high-nitrogen fertilizer mid-season. As leeks grow, mound soil around the stem to encourage longer white portions, and harvest when they are approximately 1" in diameter for the best flavor and texture.