Potatoes are a staple crop, but their cultivation involves more than simply dropping a seed in the ground. The common term “seed potato” actually refers to a tuber or a piece of a tuber, not a botanical seed. Proper planting technique is important because it directly influences the number of new potatoes that will form, setting the stage for a successful harvest. Understanding the entire process is the key to maximizing your yield.
Preparing Tubers for Planting
Before planting, seed potatoes benefit from “chitting,” which encourages the development of short, sturdy sprouts. This is done by placing the tubers in a light, airy, and frost-free location for several weeks. Chitting gives the plant a jump start, often leading to an earlier harvest.
Larger seed potatoes should be cut into smaller pieces, ensuring each section weighs about 1.5 to 2 ounces and contains at least one or two “eyes” (the indentations where sprouts emerge). Use a clean knife to prevent disease spread. After cutting, the pieces must be cured—allowed to dry for two to three days at room temperature—until a tough, protective callus forms over the cut surface. Curing prevents the cut pieces from rotting in the soil before they establish roots.
Initial Planting Depth and Spacing
The initial planting depth for seed potato pieces is typically four to six inches below the soil surface. This depth insulates the tubers from temperature fluctuations and allows space for root growth before the next stage of depth management begins. Planting can be done by digging individual holes or by creating a trench six to eight inches deep, which is then only partially filled with soil after planting.
Position the seed pieces with the cut side down and the sprouts (eyes) facing upward. Proper spacing is necessary to ensure each plant has adequate access to nutrients and light. Space individual seed pieces 10 to 15 inches apart within the row. Rows should be two to three feet apart to allow room for growth and cultivation. Initially, cover the seed pieces with only about four inches of soil, ensuring sprouts emerge easily while leaving space for future depth adjustments.
Hilling: The Ongoing Depth Management
Hilling is a continuous practice that manages potato depth long after initial planting. This technique involves gradually pulling or adding soil, compost, or mulch around the base of the growing plant stems. The primary reason for hilling is to prevent developing tubers from being exposed to sunlight, which causes them to turn green and produce the toxic compound solanine.
Hilling also increases yield by encouraging the formation of new tubers, which develop along the underground stem portion (known as stolons). Burying the stems lengthens the area where new potatoes can form. The first hilling should occur when the stems reach six to eight inches high. Add enough material to cover the stem, leaving only the top few inches of leaves exposed. Repeat this process every few weeks, or whenever the plants grow another eight to twelve inches, continuing until the plants begin to flower.