The success of a potato harvest begins long before the seed piece is placed in the soil, relying on a sequence of preparation steps and a single, important planting orientation. The potato, a tuber that is botanically a modified underground stem, grows new plants from specialized buds called “eyes.” Understanding how to handle these eyes is the difference between a robust, fast-growing plant and a weaker one. This process involves careful preparation, which directly affects the plant’s initial energy expenditure and overall yield.
Preparing Seed Potatoes for Planting
The initial step in preparing a larger seed potato is “chitting,” or pre-sprouting, which encourages the eyes to develop sturdy, short, dark green sprouts before planting. This is achieved by placing the seed potatoes in a bright, cool location, ideally between 60 and 70 degrees Fahrenheit, for two to three weeks until the sprouts are about a half-inch long. Whole seed potatoes smaller than a golf ball can be planted whole, but larger ones should be cut into pieces.
Each cut section should weigh around 1.5 to 2 ounces and contain at least one or two healthy sprouts or eyes. Cutting the seed potato increases the number of plants you can grow but also exposes the moist, starchy interior to potential soil-borne diseases and rot. To mitigate this risk, the cut pieces must be “cured” for one to two days in a well-ventilated, dry area, allowing a protective, leathery callus layer to form over the fresh wounds. This hardening process seals the cut surface, preventing pathogens from entering the seed piece.
The Importance of Sprout Orientation
When planting, the sprout orientation must be up. The sprouts emerge from the eyes and are the plant’s future stems and leaves, naturally growing toward light (positive phototropism). Planting the seed piece with the sprouts facing the soil surface allows the young shoot to immediately begin its upward growth.
If the sprout is planted facing down or sideways, the plant must expend stored energy to curve the sprout before ascending toward the surface. This unnecessary exertion slows emergence and diverts resources away from initial root development. Upward orientation is important because the new potatoes, or tubers, form on stolons that grow from the underground portion of the main stem. A strong, straight start is beneficial for the entire plant structure, promoting quicker emergence and a more vigorous start to the growing season.
Final Steps: Depth, Spacing, and Covering
The prepared seed potato pieces are typically planted in a trench that is about four to six inches deep. This initial planting depth is sufficient to protect the seed piece while allowing the sprout to reach the surface without undue strain. Deeper planting is sometimes used for later-season varieties or in drier soils to offer better moisture retention.
Spacing between the seed pieces in the trench should be approximately 10 to 15 inches apart, with rows separated by 24 to 36 inches to allow for sufficient airflow and future maintenance. Closer spacing tends to produce more numerous but smaller potatoes, while wider spacing results in fewer but larger tubers. After placing the seed piece with the sprouts pointing up, the trench is covered lightly with only two to four inches of soil. This shallow initial covering encourages rapid emergence, which is important for disease prevention, and leaves ample space in the trench for the subsequent practice of hilling soil around the growing plants.