A sweet potato growing shoots often raises questions about its edibility. This root vegetable, Ipomoea batatas, is a storage root, not a true tuber like the common white potato. Sprouting is a natural biological process indicating the end of the sweet potato’s dormancy period. It is a sign the root is attempting to grow a new plant, with visible shoots seeking light to photosynthesize.
The Biology Behind Sprouting
Sprouting is the sweet potato’s way of breaking dormancy, triggered primarily by environmental conditions. The main catalysts are temperature and humidity levels that mimic spring planting. Temperatures above 60°F, especially those rising above 70°F, signal the root to sprout. High humidity further accelerates this process by providing the necessary moisture for growth.
Once triggered, the root’s stored starch converts into soluble sugars to fuel the growing sprouts. This metabolic change consumes the root’s reserves, which is why older, heavily sprouted sweet potatoes may feel lighter. To extend shelf life, sweet potatoes should be stored in a cool, dark, and dry environment. The ideal storage range is between 55°F and 60°F, which effectively slows metabolism and maintains dormancy. Avoiding storage near sources of ethylene gas, released by ripening fruits, can also help suppress sprouting.
Eating Sprouted Sweet Potatoes
A primary concern is whether a sprouted sweet potato is safe to consume. Unlike the common potato, which produces the toxic compound solanine when it sprouts, the sweet potato does not produce this glycoalkaloid. Sweet potatoes belong to the Convolvulaceae (morning glory) family, and their sprouts are not toxic. Therefore, a sweet potato with small sprouts is safe to eat, provided the rest of the root is firm.
While safe, the quality of the root declines as sprouting progresses. The conversion of starch to sugar, while initially increasing sweetness, also draws moisture away from the flesh. This loss of reserves can cause the sweet potato to become soft, shriveled, or dry and pithy when cooked. For the best culinary results, remove the sprouts before cooking, as they can sometimes develop a slightly bitter flavor.
The sweet potato should only be discarded if it shows clear signs of spoilage independent of sprouting. Visible mold, a mushy or excessively soft texture, an unpleasant odor, or significant discoloration indicate the root is past its prime. If the sweet potato remains firm and only has small sprouts, it can still be prepared and enjoyed, though its texture may be slightly different.
Growing Sweet Potatoes from Sprouts
A sprouted sweet potato provides a simple opportunity for home gardening, as the shoots can be used to grow new plants. These shoots, known as “slips,” are the preferred planting material, as the whole root is typically not planted directly. The process begins by placing the sweet potato in a jar of water or moist soil, keeping it in a warm, bright location.
After a few weeks, the sweet potato will produce multiple slips that grow leaves and small roots. Once the slips reach four to six inches in length, they should be gently twisted or cut away from the parent root. These separated shoots are then placed in a glass of water for about a week to encourage the development of strong, fibrous roots. When the new roots are approximately an inch long, the slips are ready to be planted outdoors in warm soil to begin producing a new harvest.