A seed potato is not a true botanical seed but rather a small potato tuber used for vegetative propagation. Planting these tubers ensures the new plant is a genetic clone of the parent, which is the standard method for growing potatoes. Growing from true potato seeds would result in unpredictable variations and a loss of desirable traits. Getting started with a new planting season requires securing the right stock to ensure a healthy and abundant harvest.
Sourcing Certified Seed Potatoes
The most reliable way to begin a potato crop is by acquiring certified seed potatoes. The term “certified” means the tubers have been rigorously inspected by agricultural agencies for common and devastating potato diseases, including viruses, bacterial ring rot, and late blight. This certification process minimizes the risk of introducing pathogens that could infect your soil and future crops.
These high-quality tubers are typically available for purchase through several specialized outlets. Look for them at established local garden centers, through mail-order agricultural catalogs, or from reputable online seed and plant suppliers. Some local farm cooperatives also offer certified seed stock, which can be a good source for regional varieties. Using certified stock helps safeguard your garden from persistent soil-borne illnesses that are difficult to eradicate once established.
Selecting and Preparing Seed Potatoes for Planting
Once acquired, the seed potatoes often require some preparation before they are planted. Small tubers, roughly the size of a chicken egg (about 1.5 to 2 inches in diameter), can be planted whole. Larger potatoes can be cut into smaller sections to increase the total number of plants you can grow from your stock.
When cutting larger tubers, it is important to ensure each piece weighs at least two ounces and contains a minimum of one or two “eyes,” which are the dormant growth buds. Use a clean, sharp knife for this process to avoid inadvertently spreading any potential pathogens. Cutting the seed potato increases the number of planting units and utilizes the stored starch in each piece to fuel the initial growth.
After cutting, the pieces should be allowed to “cure” for two to three days in a cool, dark, and well-ventilated area. Curing allows the cut surfaces to dry out and form a protective callus layer, which helps prevent rot when the pieces are planted in the soil. This hardened layer acts as a barrier against soil-borne fungi and bacteria.
A further step in preparation is “chitting,” or pre-sprouting, which encourages earlier and more uniform emergence after planting. To chit, place the tubers or cut pieces eye-side up in a tray in a location that is cool, approximately 50 to 60 degrees Fahrenheit, and receives indirect light. This cool, bright environment encourages short, stout, and dark-colored sprouts, which are preferable to the long, pale sprouts that develop in total darkness.
Risks of Using Non-Certified Potatoes
A common question for new gardeners is whether they can simply plant potatoes purchased from a grocery store. This practice carries significant risks and is generally not recommended. Commercial potatoes are not grown under the strict disease inspection standards required for certified seed.
Planting non-certified stock can introduce viruses into your garden soil, which can persist and infect future crops of potatoes, tomatoes, and other related plants. These viruses are often transmitted by insects like aphids and can severely reduce the yield and quality of your harvest.
Furthermore, many commercially grown potatoes are treated with chemical sprout inhibitors, such as chlorpropham (CIPC), to extend their shelf life. These inhibitors prevent the tubers from sprouting in storage, making them unreliable or completely useless for planting. Even if they eventually sprout, the chemical residue can lead to stunted or poor growth in the resulting plants.