Potatoes do best in rich well-cultivated, well-drained soil that hasn't been planted with potatoes for a few years. Plant sets 4-5 inches deep and 12-15 inches apart in rows 2 feet apart. (NOTE: Kennebec sets should be planted closer to hold down tuber size.) Keep rows weeded but do not cultivate too deeply. Tubers form close to the soil surface, so it may be necessary to mound 2-3 inches of soil over the row as they grow to keep the sun from turning them green and bitter. Dig when tubers are large enough to make it worth your while--usually 7-8 weeks after planting. Do not dig up the entire plant.
Carefully dig larger tubers, leaving the smaller ones to continue to grow. Harvest for winter storage when plant tops begin to dry. Leave tubers in the garden for a day to cure the skins, then store in a cool, dark, airy place.