The practice of sprouting potatoes, often called “chitting” or pre-sprouting, encourages the seed potato to develop short, vigorous shoots before planting. This technique provides a significant head start to the plant’s growth cycle, effectively shortening the time between planting and harvest. Breaking the potato’s natural dormancy indoors ensures a strong, early emergence once conditions are favorable. This accelerated growth results in a more robust plant and an earlier, more reliable yield compared to planting dormant tubers.
Selecting and Curing Seed Potatoes
The first step is choosing the correct material for planting; certified seed potatoes are the superior choice over standard grocery store potatoes. Certified stock is guaranteed to be disease-free and has not been treated with sprout-inhibiting chemicals that can prevent the chitting process. Grocery store potatoes often carry soil-borne diseases that can contaminate your garden, making the investment in certified seeds worthwhile for long-term garden health and better harvests.
Once acquired, the seed potatoes should be warmed up, or “cured,” before inducing sprouts. This involves moving them from cold storage to a warmer environment for a couple of days. The ideal size for a seed potato is roughly between 1.5 and 2.5 ounces, or about the size of a chicken egg, as this size contains sufficient food reserves for initial growth. Larger potatoes can be cut, but smaller ones are planted whole for the best vigor.
The Step-by-Step Sprouting Process
To begin chitting, the tubers require specific environmental cues to trigger healthy sprout development. The most effective method involves placing the seed potatoes in a location that provides bright, indirect light, which prevents the shoots from becoming long, pale, and weak. The desired temperature range for this stage is cool, ideally between 50–60°F (10–15°C).
Arrange the potato with the “rose end”—the end containing the most eyes—facing upward. Placing the tubers in a single layer in shallow trays or old egg cartons helps keep them stable and ensures they receive adequate light. This chitting process typically takes about two to four weeks, depending on the conditions.
A successful sprout, or “chit,” will be short, thick, and dark green or purplish, measuring between a half-inch to an inch long. These stocky sprouts are robust enough to withstand planting and quickly establish themselves in the soil. If the sprouts are long and white, it indicates they were kept in conditions that were too dark, and they should be removed to encourage the growth of stronger sprouts.
Preparing Sprouted Pieces for Soil
For any seed potato larger than an egg, cutting it into smaller pieces is recommended to maximize the number of plants grown. Each piece should be cut to a size of at least 1.5 ounces and must contain one to two healthy, well-developed sprouts. Ensure the knife used for cutting is clean to prevent the transmission of diseases between tubers.
After cutting, the pieces must be left to “cure” for one to two days in a well-ventilated, dry location, out of direct sun. This curing period allows the cut surface to dry and form a protective, leathery layer, known as a callus. This callus acts as a barrier against soil-borne pathogens and rot, especially if the soil is cool and moist during planting. Avoid snapping off the new sprouts during handling, as this depletes the potato’s energy reserves and delays growth.
Final Planting Instructions
The prepared seed potato pieces are ready for the garden once the danger of a hard frost has passed and the soil temperature reaches a minimum of 42°F (6°C). The sprouted pieces should be placed in a trench or hole about four inches deep, with the sprouts pointing upward. For proper development and yield, space the pieces approximately 12 inches apart within the row.
Immediately following planting, water the soil gently to settle the earth around the seed pieces, ensuring it does not become waterlogged. Once the emerging green shoots reach a height of six to eight inches above the ground, begin the initial hilling process. This involves drawing up surrounding soil around the stems until only the top few inches of foliage are visible. Hilling encourages the formation of new potatoes along the buried stem and protects developing tubers from light.