Whether you're growing leeks from seed (too late this fall, so wait till spring) or start (better get them in now!), you'll have to grow them in a trench if you want a nice bit of white. Why? Because covering the base of the leek with dirt blocks it from the sun and leaves the column of the leek soft and white. The same practice is done with frisee or endive in the field. If you do NOT plant in trenches, you'll still grow leeks, but the white bit will be super short and you'll be disappointed. Watch this video to see how leeks are planted and then covered as they grow & let me know what you think! It's my first ever how-to garden video and I hope to make more as time allows. How to Grow Leeks.