The appearance of sprouts, often called “eyes,” on older potatoes signals that the tuber is physiologically ready to begin its next life cycle. Instead of discarding these spuds, they can be repurposed as seed potatoes to start a new crop in the home garden. This practice is an economical and effective way to utilize kitchen leftovers, provided the potatoes are free from disease. By following specific preparation and planting guidelines, gardeners can successfully convert these sprouted tubers into productive plants.
Preparing Sprouted Potatoes for Planting
Preparing the sprouted tuber involves cutting large potatoes into smaller sections, as planting the entire potato is inefficient and can lead to a weaker plant. Each resulting piece, or “seed piece,” should weigh approximately 1.5 to 2.5 ounces. Each piece must contain at least one, and preferably two or three, prominent eyes or sprouts.
Using a clean knife, cut the potato into block-shaped pieces, ensuring a firm, healthy portion of the original tuber remains attached to the sprouts. Small potatoes, roughly the size of an egg, can typically be planted whole without cutting. After cutting, the seed pieces must be allowed to “cure” for a period before they are introduced to the soil.
Curing involves letting the cut surfaces dry out in a cool, airy, and dark place for one to seven days, which promotes the formation of a protective, leathery layer. This hardened layer, or callus, acts as a barrier against soil-borne pathogens and helps prevent the seed piece from rotting once it is placed underground. Properly curing the seed pieces reduces the risk of disease transmission and decay, ensuring a higher rate of successful sprout emergence.
Optimizing Planting Site and Timing
Potatoes are a cool-season crop that thrives when planted in early to mid-spring, once the threat of a hard frost has passed. The soil temperature is a more accurate indicator than the calendar, and planting should occur when the ground temperature is consistently above 45°F, ideally reaching 50°F. Planting in soil that is too cold or overly wet increases the risk of the seed pieces decaying before they can sprout.
Potato plants require a minimum of six to eight hours of direct sunlight each day to support the vigorous top growth that feeds the developing tubers. The soil should be loose, well-draining, and cultivated to a depth of six to eight inches to accommodate the developing root system. Potatoes perform best in soil with a slightly acidic pH range, typically between 5.5 and 6.0, as a higher pH can increase the incidence of potato scab. Before planting, incorporating a balanced, low-nitrogen fertilizer into the prepared soil can provide the initial nutrients needed for successful tuber development.
Step-by-Step Planting Technique
The prepared seed pieces are typically planted in trenches or individual holes dug into the prepared soil. A standard planting depth is between three and five inches. The seed piece should be placed into the trench with the cut side facing down and the sprouts, or eyes, pointing upward toward the soil surface.
Adequate spacing between the seed pieces is necessary to ensure each plant has sufficient resources for growth and tuber formation. Pieces should be spaced approximately 10 to 12 inches apart within the row. If planting multiple rows, a distance of 30 to 36 inches between rows allows for proper hilling later in the season and provides space for the mature foliage.
After placing the seed pieces, cover them with about three to four inches of loose soil or a soil-compost mix, leaving the remainder of the trench partially unfilled. This initial covering protects the seed while allowing the soil to warm and the sprouts to emerge. Watering the newly planted area thoroughly helps to settle the soil and initiates the growth process, but it is important to avoid saturated conditions, which could lead to rot.
Initial Care and Hilling
Consistent soil moisture is necessary for healthy potato growth, particularly as the plants develop their underground tubers. The soil should be kept evenly moist but never waterlogged, which can inhibit the plant’s ability to breathe and lead to reduced yield. Generally, one inch of water per week from rain or supplemental irrigation is adequate, though sandy soils may require more frequent watering.
The most specialized maintenance technique for potatoes is called “hilling,” which involves mounding additional soil around the base of the emerging plant stems. This process is performed when the green shoots reach a height of six to eight inches above the ground. Hilling serves the purpose of protecting the newly forming tubers, which develop along underground stems called stolons.
Tubers exposed to sunlight will turn green and accumulate glycoalkaloids, a bitter compound that is toxic if consumed in large amounts. By mounding an additional three to six inches of soil or organic material around the stems, the growing potatoes are kept in complete darkness and protected from this greening process. Hilling should be repeated every time the plant grows another six to eight inches, continuing until the soil mound reaches six to eight inches in total height.