3. Raised Bed
Loosen the soil in the bottom of a half-filled raised bed. Space seed potatoes about 12 inches apart in all directions and bury them 3 inches deep. As the potatoes grow, add more soil until the bed is filled. If possible, simplify harvest by removing the sides.
Pros: This method yielded the largest harvest in my trials, and the potatoes were uniformly large. Raised beds are a good choice where the garden soil is heavy and poorly drained.
Cons: The soil to fill the bed has to come from somewhere—and it takes a lot.