The appearance of sprouts, often called chits or eyes, on a potato tuber signals the plant’s readiness to begin a new growth cycle. This sprouted tuber is referred to as a “seed potato,” the vegetative material used to propagate the crop. Planting potatoes in this state is the intended method for cultivation. While it is possible to plant a potato found sprouting in a pantry, it must be prepared correctly to ensure a successful harvest.
Preparing Sprouted Potatoes for Planting
Before planting, the seed potato must be assessed to maximize the number of new plants and prevent disease. Any potato larger than a golf ball should be cut into blocky pieces, weighing between 1.5 and 2 ounces. Each segment must contain at least one to two firm, healthy sprouts or “eyes” to ensure a viable new plant develops.
Use a clean, sharp knife to divide the potato, ensuring each piece is roughly two inches square. While planting whole tubers is possible for smaller potatoes, cutting yields more plants from the same material. The newly cut pieces must then undergo curing or callousing before they are placed in the soil.
Curing involves laying the pieces in a single layer in a dry, well-ventilated area away from direct sunlight for 24 to 48 hours. The cut surface forms a thick, protective callus, which acts as a barrier against soil-borne pathogens and prevents the seed piece from rotting. This step improves the survival rate and initial vigor of the developing plants.
Planting Technique and Site Selection
Potatoes perform best in a location that receives full sun (a minimum of six to eight hours daily). The ideal planting medium should be loose, well-draining, and rich in organic matter, as compacted soil can lead to misshapen tubers. A slightly acidic soil pH, between 5.8 and 6.5, is beneficial for optimal growth and helps deter certain diseases.
A trench or hole should be dug approximately six to eight inches deep, though a shallower trench can be used if the gardener plans to “hill” the plants later. Place each cured seed piece with the cut side facing down and the sprouts pointing upward toward the soil surface. This orientation allows the sprouts to efficiently grow toward the light, promoting faster emergence.
Spacing is important for tuber development; seed pieces are typically placed about 12 inches apart in the row. This distance provides enough room for the underground tubers to develop fully. After placing the seed pieces, cover the trench with only three to four inches of soil initially, leaving the remainder for later maintenance.
Post-Planting Management and Harvesting
Once potato plants emerge and reach a height of six to eight inches, the process of “hilling” must begin. Hilling involves gently mounding additional soil or organic material, such as straw, around the base of the stems, leaving only the top few inches of foliage exposed. This technique is repeated every few weeks as the plant grows, particularly before flowering.
The primary purpose of hilling is to shield developing tubers from sunlight, preventing them from turning green and producing the toxic compound solanine. Mounding the soil up the stem encourages the plant to produce more tubers, as potatoes form along the buried stem portions. A consistent supply of moisture (one to two inches of water per week) is important, especially when plants flower and begin setting tubers, since irregular watering can cause misshapen or cracked potatoes.
For the main harvest, potatoes are ready when the foliage naturally turns yellow and dies back, typically two to three weeks after this occurs. This period allows the potato skins to thicken, a process known as “setting the skin,” confirmed by a skin that remains firmly attached when rubbed gently. After digging the mature tubers, they should be cured in a dark, humid environment (ideally 45–60°F) for about two weeks to heal minor abrasions and prepare them for long-term storage.