The process of encouraging a potato tuber to produce short, sturdy sprouts before planting is known as chitting, or pre-sprouting. This technique accelerates the potato’s natural growth cycle, giving the crop a significant head start in the growing season. By initiating growth indoors under controlled conditions, you can shorten the time from planting to harvest, potentially resulting in earlier harvests and greater overall yields.
Preparing Seed Potatoes for Accelerated Sprouting
The first step is selecting certified seed potatoes, which are guaranteed to be disease-free and lack the chemical sprouting inhibitors found on grocery store potatoes. These inhibitors are designed to keep the potatoes dormant during transport and storage, making them slow and unreliable for planting purposes.
Before sprouting, potatoes must be brought out of dormancy, usually by removing them from cold storage. If seed potatoes are larger than a chicken egg, cut them into pieces to maximize the number of viable planting units. Each resulting seed piece should weigh at least 1.5 to 2 ounces and contain a minimum of two healthy eyes.
Allow the cut surfaces to dry and form a protective, cork-like layer, a process called suberization, which takes about 24 to 48 hours. This curing step prevents water loss and helps to protect the seed piece from rotting once it is placed in the sprouting environment or planted in the soil. Once cured, the tubers are ready for environmental controls that promote rapid sprout development.
Creating the Ideal Environment for Rapid Sprouting
To encourage the fastest and healthiest sprout development, you must provide warmth and light. The optimal temperature range for rapid sprout initiation is between 60 and 70 degrees Fahrenheit (15 to 21 degrees Celsius). Warmer temperatures quickly break the potato’s dormancy and signal it to begin growth, making a warm room or kitchen counter an ideal location.
The type of light provided ensures the sprouts grow short, stocky, and dark green, rather than long, pale, and fragile. Place the potatoes in an area that receives bright, indirect light for at least 10 to 12 hours a day. Avoid direct sunlight, as intense heat can damage the tubers and promote the formation of solanine, a compound that causes the potato skin to turn green.
Arrange the tubers in a single layer with the majority of the eyes facing upward, using shallow trays or old egg cartons to keep them stable and separated. Maintaining good air circulation around the tubers is helpful to prevent any moisture buildup that could lead to fungal growth or rot.
Monitoring Sprout Development and Troubleshooting
The chitting process usually takes between two and four weeks, though the exact time frame depends on the potato variety and the consistency of the environmental conditions. The sprouts are ready when they are short, sturdy, and dark green, generally measuring about one-half to three-quarters of an inch in length. These strong chits will be able to withstand the planting process without easily breaking off.
If your potatoes fail to sprout within the expected timeframe, it is often due to deep dormancy from prolonged cold storage. They may need an initial week in a dark, slightly warmer location to fully wake up. If you notice the sprouts becoming long and spindly (etiolation), this indicates insufficient light exposure, and the potatoes should be moved to a brighter location immediately.
If the weather delays your planting date and the sprouts are growing too long, the growth rate can be slowed down by moving the potatoes to a cooler area while still maintaining some indirect light. Handle the tubers carefully once the sprouts are established, as any damage to these initial growths can reduce the plant’s overall vigor and potential yield.