Soil temperatures should be between 45 and 70 degrees F at planting time. Planting into cold soils delays emergence and increases the risk of seed piece decay. Although rainfall often suffices, irrigation may produce highest yields. Potatoes need 18 to 30 inches of water to mature. Potatoes are shallow rooted, with most roots being in the upper foot of soil.
Potatoes are sensitive to water stress.
Well-drained, light textured soils, such as sandy loams or loamy sands, generally produce the highest quality potatoes. Good-Quality Seed Potatoes are vulnerable to several diseases, including blackleg, bacterial ring rot, and viruses, which can be transmitted in infected seed. To avoid such problems, certified potato seed is recommended. Not guaranteed to be disease free, potatoes certified by State agencies have shown no more than an allowable tolerance level for disease symptoms. For certain diseases, such as ring rot, the tolerance level is zero.