The practice of encouraging sprouts to grow on seed potatoes before planting is widely known as chitting or greensprouting. This technique initiates the development of short, sturdy shoots, called chits, while the tuber is still indoors. By controlling the environment, the gardener ensures that the seed potato is physiologically ready for rapid growth as soon as it enters the soil. This preparation helps the plant establish itself quickly, which is especially valuable in regions with shorter growing seasons.
Understanding the Benefits of Sprouting
The primary purpose of chitting is to give the potato plant a head start over an unsprouted tuber. This allows the plant to emerge from the soil more quickly, which directly impacts the harvest time. Studies show that pre-sprouted potatoes can emerge up to five days earlier than those planted directly from cold storage. This faster emergence is often linked to an earlier harvest, sometimes by as much as two weeks, which is particularly beneficial for early-season varieties. By encouraging the development of strong, hardy sprouts before planting, the tuber can focus its energy on growing the foliage and forming new potatoes more efficiently once in the ground, contributing to a higher overall yield.
Essential Preparation Before Sprouting
Before the chitting process can begin, the seed potatoes must be selected and prepared. It is important to source certified, disease-free seed potatoes rather than using regular store-bought tubers, as these may carry diseases or have been treated with sprout-inhibiting chemicals. The first step involves identifying the “rose end” of the potato, which is the blunt end where the majority of the small indentations, or “eyes,” are concentrated. If the seed potatoes are large—about the size of a hen’s egg or larger—they can be cut into smaller pieces to yield more plants. Each piece should be cut to contain at least one or two strong eyes and enough tuber mass to sustain the emerging sprout. After cutting, the pieces must be allowed to “cure” or dry for one to three days at room temperature. This curing process forms a protective, cork-like layer over the cut surface, which helps prevent rot and fungal infection once the pieces are planted.
Detailed Guide to the Sprouting Process
The chitting process requires balancing light and temperature to produce short, stocky sprouts. To begin, place the prepared seed potatoes or cut pieces in a single layer with the rose end facing upward. Shallow trays or old egg cartons are ideal for keeping the tubers upright and separated. The tubers should then be placed in a cool, bright, and frost-free location, such as a cool sunroom or a bright windowsill that does not receive direct, scorching sunlight. The ideal temperature range for chitting is cool, between 50°F and 60°F (10°C and 15°C). Temperatures that are too warm, above 70°F, can cause the potatoes to shrivel or produce weak, spindly sprouts. The light is crucial for preventing the sprouts from becoming long, pale, and fragile, a condition known as etiolation. Bright, indirect light encourages the sprouts to develop a short, knobby, green or purple color, which indicates a sturdy structure capable of withstanding planting. The chitting period generally lasts between three and six weeks, with the potatoes ready for planting when the chits are about a half-inch to one inch long.
Transitioning Sprouted Potatoes to the Garden
Once the chits are short and colored, the seed potatoes are ready to be moved into the garden or container. The sprouts are delicate, so handling the tubers with care is necessary to ensure the chits do not break off. If a sprout is accidentally knocked off, the potato will still grow, but it will lose the advantage of the pre-sprouting process. Potatoes are a cool-weather crop and should be planted two to four weeks before the typical last frost date, as they tolerate cool soil better than tender crops. Plant the tubers in a prepared trench or hole 6 to 8 inches deep, with the chits facing upward toward the soil surface. Spacing the seed potatoes about 12 inches apart ensures adequate room for tuber development and air circulation. The initial layer of soil used to cover the planted tuber should be loose and gently applied to avoid damaging the new growth.