How to plant Potatoes. Planting potatoes in a potato drill or ridge. A drill is a shallow furrow for seed potatoes, it will look like rows of mounded soil and it can be made using a furrower or more easily by dragging a ridging hoe in a straight line through the earth. Seed potato tubers are then placed in the drill and covered over. Plant the potato 10 to 15cm deep into good fertile soil. Planting in ridges is recommended as it makes them much easier to earth up.