Since the average American eats about 125 pounds of potatoes and potato products each year, Irish potatoes are one of America’s most popular vegetables. Irish potatoes are a cool season crop; they grow best in early spring and late fall when the days are warm and the nights are cool. Although the potato is a cool-season crop and the edible part of the plant is an underground stem called a tuber (not a root), the tops of the plant will not withstand frost. Potatoes need full sun for best production.
Soil Preparation and Fertilization
Potatoes do best in a loose, well-drained, slightly acid soil. Poorly drained soils often cause poor stands and low yields. Heavy soils can cause tubers to be small and rough.
Remove rocks, large sticks and trash from the soil before spading. Spade the soil 8-12 inches deep. Turn the soil over to cover all plant material. Work the soil into beds 10-12 inches high and 36 inches apart (see Figure 1). Bedding is very important for drainage.
Because potatoes need adequate fertilizer in early season, apply most of the fertilizer just before planting. Use 2 to 3 pounds of complete fertilizer such as 10-20-10 for each 30 feet of row in bands 2 inches to each side and 1 inch below the seed piece. The fertilizer should not touch the seed piece. To apply the fertilizer, flatten the beds so they are 6 to 8 inches high and 10 to 12 inches wide (see Figure 2).
Using the corner of a hoe or stick, open a trench about 4 inches deep on each side of the bed. Apply half of the fertilizer (about 2 cups for each 30 feet of row) in each trench. The seed pieces will be planted in a row between the two bands of fertilizer (see Figure 3).