The pit for the bed may be dug six inches deep and as long as desired. Place five or six inches of sand in the bottom of the pit. Place the potatoes on the sand as closely as possible without touching. The potatoes then should be covered with sand to one inch above the potatoes. Roots of the same size should be bedded together so that the covering will be of equal depth.
Sand is the best media for the production of strong, stocky slips.
To increase soil temperature in the beds, place a black plastic film on the bedding material and leave until slips start growing. It is advisable to have a cloth or polyethylene cover to place over open beds during cold spells. A pre-bedding heat treatment of seed root stock increases slip production. Seed stock should be held in storage for three to four weeks before bedding at a temperature of 85 to 90 degrees F with humidity at 85 percent. All varieties respond to the heat treatment, and with poor slip producing cultivars such as Centennial, preheating of seed stock is almost a necessity.