Getting a potato ready for planting often involves a process called “chitting,” which is the pre-sprouting of the potato tuber before it enters the soil. This technique gives the plant a significant developmental advantage, allowing it to begin vegetative growth sooner after planting. By initiating sprout growth indoors, gardeners aim to achieve an earlier harvest and potentially increase the final yield. This preparation step optimizes the potato’s growing season, especially in regions with shorter summers.
Selecting and Preparing the Seed Material
The foundation of successful potato rooting begins with the selection of the seed material. It is recommended to use certified seed potatoes, which have been specifically grown and inspected to be disease-free and not treated with sprout-inhibiting chemicals. Grocery store potatoes may carry diseases or have been sprayed with substances designed to prevent sprouting. Inspect the tubers for small indentations, known as “eyes,” which are the dormant buds from which the new shoots will emerge.
Once suitable tubers are chosen, decide whether to root them whole or cut them into smaller pieces. Smaller tubers, typically those less than two ounces, are often rooted whole to prevent decay and provide the emerging sprouts with maximum stored energy. Larger tubers are more efficiently utilized by cutting them, ensuring each resulting piece is approximately two ounces in weight.
When cutting, make sure each section contains at least one or two well-defined eyes. Using a clean, sharp knife minimizes the risk of transferring pathogens between tubers during the process.
Immediately after the tuber is cut, the pieces must undergo a process called “curing” before rooting begins. Curing involves leaving the cut pieces in a warm, humid, and dark area for one to three days. This allows the exposed flesh to dry out and form a protective layer, or callus, which acts as a barrier against rot and soil-borne diseases once planted.
Creating the Ideal Sprouting Environment
The environment established for chitting is paramount in producing the desired short, sturdy sprouts, often called “chits.” The ideal conditions combine bright, indirect light with cool ambient temperatures. Direct sunlight is too intense and can potentially scorch the developing eyes or cause the tuber to dry out prematurely.
Maintaining a temperature range between 50°F and 60°F (10°C to 15°C) encourages the potato to produce thick, robust, often purplish-green sprouts. If the environment is too dark or too warm, the potato will instead develop long, thin, pale white shoots. These weak sprouts, known as etiolated growth, are easily damaged during planting and do not provide the strong head start the chitting process aims for.
To facilitate the rooting process, the prepared seed pieces need to be placed in a stable position with the majority of the eyes facing upward. This arrangement maximizes light exposure to the eyes and prevents the tubers from rolling. Common methods include:
- Utilizing old egg cartons.
- Shallow trays.
- Spreading them out in a single layer on a flat surface.
No additional moisture or soil is required during this pre-sprouting phase, as the tuber itself contains all the necessary nutrients and water reserves for initial growth. The chitting process typically takes between two and four weeks, depending on the variety of potato and the consistency of the environmental conditions.
The potato pieces are ready to be moved outdoors when the sprouts have reached a length of approximately one-half to one inch. At this size, the chits are firm and have accumulated enough energy to withstand the transition to the garden soil. Allowing the sprouts to grow much longer increases the risk of them snapping off during handling.
Moving the Rooted Potato to Soil
Transitioning the rooted potato pieces to the garden requires careful timing to avoid late-season frosts, which can kill the emerging foliage. The soil temperature should ideally be above 45°F, and the threat of freezing temperatures should have passed in your specific area. Planting too early risks damaging the delicate new growth.
When planting, dig a furrow or hole that is approximately four to six inches deep. The orientation of the seed piece is important: always place the potato with the newly developed sprouts facing directly upward toward the soil surface. This ensures the shoots have the shortest path to light and begin growing immediately.
Gently cover the seed piece with soil, taking care not to break the brittle chits during backfilling. A light, gentle watering helps settle the soil around the piece without disturbing the sprouts or causing the tuber to rot. This initial planting establishes the base for the potato plant, which will require subsequent mounding of soil, known as hilling, as it grows.