Potato

Environmental Preferences
  • Light: Sunny
  • Soil: Well-drained with moderate organic matter
  • Fertility: Medium-rich
  • pH: 5.0 to 6.5
  • Temperature: Cool (55 to 65 degrees F.)
  • Moisture: Uniform moisture (especially while tubers are developing)
Culture
  • Planting: 1 1/2 to 2 ounce seed pieces with at least one good eye are planted in early spring or late summer
  • Spacing: 10 to 12 inches X 24 to 36 inches
  • Fertilizer needs: Medium-heavy feeder; add high phosphorus fertilizer (1 1/2cups of 1-20-10 per 10 feet of row) before planting
Cultural Practices

Both white-skinned and red skinned potatoes can be grown as an early crop for new potatoes and as a late crop for storage. Depending on your location, plant potatoes 21 to 30 days before the last frost. Hard frosts and freezes may set back growth. Potatoes prefer cool springs and moisture throughout the growing season. Crops can be successfully planted 3 to 4 months before the first fall frost, but yield may be reduced.

Avoid planting potatoes where the lawn has been turned under because grub worms may damage developing tubers unless soil insecticides are used.

A soil pH of 6.0 to 6.5 is most desirable; however, the occurrence of scab disease will be less when pH is between 5.0 to 5.2. In addition to the base application of fertilizer, add about 1/4 pound of 10 for each 75 feet of row. Work this into the furrow and mix with the soil before planting.

Plant only certified seed potatoes; saving your own seed potatoes is not recommended. Seed potatoes should be firm and unsprouted. Wilted or sprouted potatoes usually have less vigor from being stored under conditions that were too warm. Seed pieces for planting should be cut to about 1 1/2 to 2 ounces or into 1 inch cubes. Potatoes about 6 ounces in size will cut nicely into four pieces. Each seed piece should have at least one good bud or eye. Plant potatoes in furrows 2 to 3 inches deep.

When the plants are about 4 to 6 inches tall, they should be "dirted." Use a hoe or something similar to pull about 3 to 4 inches of soil up to the plants. The seed piece should ideally be about 6 inches beneath the surface of the soil after the dirting process. When the tops have grown too large to allow cultivation, a finishing cultivation, sometimes called "laying by" or "hilling up," is given. "Laying by" throws soil over the potatoes to prevent exposure to sunlight which can cause greening or scalding. Green potatoes taste bitter due to an alkaloid and should not be consumed.

Common Problems

  • Diseases: Early blight; scab; late blight; tuber rots; virus complex; Fusarium, Verticilliurn and bacterial wilts
  • Insects: Colorado potato beetles; flea beetles; leathoppers
  • Cultural: Green skin (sun exposure); hollow heart (alternate wet and dry conditions)
Harvesting and Storage
  • Days to maturity: 90 to 120
  • Harvest: Dig early potatoes when tubers are large enough to eat. Harvest potatoes for storage 2 weeks after the vines die down or just after the first light frost nips the vines before heavy freezing. Avoid skinning tubers when digging and avoid long exposure to light.
  • Approximate yields: (per 10 foot row) 10 to 20 pounds
  • Storage: Medium-cool (40 degrees to 50 degrees F.), moist (90 percent RH) conditions for 6 to 8 months; sprouting is a problem at higher temperatures
  • Amount to raise per person: 75 to 100 pounds (plant about 10 to 15 pounds of seed potatoes per person)
  • Preservation: Usually stored in medium-cool, moist conditions