This is my first year growing potatoes. I used organic seed potatoes (yellow finns) and they are growing gangbusters. After reading about how to grow them in the Vegetable Gardener's Bible, I decided to plant most of them in holes that I would later fill in, thinking it would be easier for me than traditional hills on top of the bed. However, I didn't realize that the foliage would be so large and abundant. Am I really supposed to cover all that greenery with loam??? I think the books say that when the plants are about 1 foot tall, cover them up so that only about 3" of foliage shows. I feel strange burying a plant's leaves. Is this really the right thing to do or have I misunderstood?