You absolutely can grow a potato from a potato, and this method is the most common way to cultivate them in a home garden. The potato you hold is actually a tuber, a modified underground stem that the plant uses for both food storage and reproduction. This storage organ contains all the necessary genetic material and energy reserves to sprout a new plant. This ensures a genetically identical copy of the parent potato and allows gardeners to easily transform a single healthy potato into an entire harvest of new tubers.
Understanding Potato Propagation
Potatoes propagate through a vegetative process, rather than sexual reproduction involving true botanical seeds. The small indentations visible on the potato’s surface are called “eyes,” which are dormant buds. When conditions are right, these buds break dormancy and sprout, forming the stems and leaves of the new plant above ground and the new potatoes below.
This method of growing from the tuber is considered asexual reproduction because it does not involve the mixing of genetic material. While a home gardener can use a healthy, non-chemically treated potato from the store, commercial growers often choose certified “seed potatoes.” These specialized potatoes are guaranteed to be disease-free and have not been treated with sprout inhibitors. Using a certified seed potato helps prevent the introduction of common potato diseases into the garden soil, ensuring a more robust crop.
Preparing the Tuber for Planting
To maximize the number of plants, larger potatoes should be cut into smaller pieces before planting. Each piece needs a sufficient mass, typically 1.5 to 2 ounces, and must contain at least one or two healthy “eyes.” Using a clean knife minimizes the risk of introducing pathogens to the exposed flesh.
After cutting, the pieces must be allowed to “cure” or dry for one to two days in a well-ventilated area, ideally between 60°F and 70°F. This curing process allows the cut surface to form a dry, protective layer known as a callous. This tough layer acts as a natural barrier, protecting the potato piece from rot and soil-borne diseases once it is planted.
Some gardeners choose to pre-sprout their potatoes indoors, a process known as “chitting,” to give the plants a head start. To chit, potato pieces are placed in a bright location, avoiding direct sunlight, with temperatures in the 60°F to 70°F range. This encourages the buds to grow short, thick, and dark green sprouts, which are preferable to the long, pale sprouts that develop in darkness. The potato pieces are ready for the garden once these sturdy sprouts reach about half an inch to one inch in length.
Planting and Ongoing Care
Potatoes should be planted soon after the last expected spring frost, when the soil temperature has warmed sufficiently. They thrive in loose, well-draining soil, such as a sandy loam, that has been amended with organic matter. Dig a trench or individual holes four to six inches deep, placing the cured potato pieces with the eyes facing upward, approximately 10 to 12 inches apart.
The process of “hilling” is important for successful potato cultivation and must be repeated as the plant grows. Hilling involves gradually mounding soil, compost, or straw around the emerging stems. This technique serves two purposes: it encourages the plant to produce more new tubers along the buried stem, and it keeps the developing potatoes covered.
Potatoes exposed to sunlight turn green and produce a mildly toxic compound called solanine, so hilling prevents this. Begin hilling when the green shoots reach six to eight inches high by pulling soil up around the plant until only the top few leaves are visible. Repeat this mounding whenever the shoots grow another six inches, until the final hill is six to eight inches high. Consistent watering is necessary, especially when the plants begin to flower, as moisture stress can lead to misshapen or hollow tubers.
Harvesting Your New Crop
The potato plant signals that the tubers are nearing maturity when the foliage begins to yellow, wither, and eventually die back. This natural decline in above-ground growth, which typically happens 70 to 120 days after planting, indicates that the plant has finished putting energy into the leaves. For long-term storage, stop watering the plants a couple of weeks before this point and wait an additional two weeks after the foliage has completely died back.
This waiting period allows the potato skins to thicken and toughen, which improves their ability to store without damage. To harvest, gently loosen the soil around the plant with a garden fork, starting a foot or more away from the main stem to avoid puncturing the potatoes. Carefully lift the tubers from the ground, brushing off any loose soil. Newly harvested potatoes can be laid out in a dark, well-ventilated space for about 7 to 10 days to finish curing, which seals any small abrasions and prepares them for long-term storage.