Chitting is the horticultural technique of pre-sprouting seed potatoes before they are planted in the garden. This process encourages the tubers to break dormancy and begin developing sprouts, or “chits,” in a controlled environment. By giving the seed potatoes a head start indoors, you ensure they are actively growing before outdoor planting, which sets the stage for a more robust crop.
The Advantage of Chitting for Potato Growth
The benefit of chitting is that it jump-starts the plant’s development, saving several weeks of growth time once the seed potatoes are placed in the soil. When dormant potatoes are planted directly, they must first break dormancy and form sprouts underground, which delays the emergence of the foliage. Chitting allows the potato to bypass this initial waiting period, leading to earlier emergence above ground.
This time savings is particularly beneficial for “first early” potato varieties, resulting in an earlier harvest. The quicker establishment of a strong plant structure also promotes higher yield potential and a more reliable crop. Earlier maturity can also help the plant avoid some common diseases, such as late blight, which becomes more prevalent as the season warms.
Setting Up the Chitting Environment
The chitting process should begin approximately four to six weeks before the intended outdoor planting date. The ideal location is a cool, frost-free space that provides ample, bright, indirect light to the tubers. A temperature range between 45°F and 55°F (7°C and 13°C) is suitable for encouraging strong, healthy sprout development.
Avoid placing the potatoes in direct sunlight, which can cause them to overheat and dry out. Storing them in a dark, warm space will cause the sprouts to become long, white, and fragile, a condition called etiolation. Shallow trays, old egg cartons, or crates are excellent containers, as they allow the seed potatoes to be placed upright and ensure good air circulation.
Step-by-Step Guide to Chitting
To begin chitting, first identify the “rose end” of the seed potato, which is the end possessing the greatest concentration of “eyes.” This end is the natural growth point and is typically the blunter end of the tuber, opposite the point where it was attached to the parent plant. Place each tuber in your container with the rose end facing upward, allowing the eyes to receive the light.
Monitor the potatoes over the next few weeks, ensuring the environment remains consistently cool and bright. The goal is to produce short, stocky sprouts that are dark green or purplish in color, indicating they are robust. If you wish to grow fewer, larger potatoes, gently rub off all but the two or three strongest sprouts when they are about a quarter-inch long. Leaving more sprouts intact generally results in a higher number of smaller-sized potatoes.
Transitioning from Chit to Soil
The chitting process is complete when the sprouts have reached a length of about a half-inch to one inch (1 to 2.5 cm). Aim to plant the chitted potatoes when the last expected frost has passed and the soil temperature has warmed to at least 50°F (10°C).
When handling the ready-to-plant potatoes, exercise care to prevent snapping off the newly formed chits. The sprouts represent the plant’s initial energy investment; breaking them forces the potato to expend stored energy to produce replacements, delaying growth. Gently place the seed potato into the prepared soil, ensuring the delicate sprouts are facing upward to continue their rapid growth toward the surface.