Sweet potato slips are not seeds; they are vegetative sprouts or vine cuttings taken from a mature sweet potato. These slips are the primary means of propagating the plant, Ipomoea batatas. Since sweet potatoes are tropical in origin and require a long, warm growing season, planting the entire tuber directly into the ground is often unsuccessful in most regions, especially those with cooler springs. The use of a slip, which is essentially a small, rooted plant, gives the crop a necessary head start, ensuring the plant has enough time to develop the large, edible storage roots before the first frost.
Primary Sources for Purchasing Slips
The most reliable source for obtaining sweet potato slips is through mail-order specialty growers and reputable seed companies. These online vendors often offer an extensive selection of varieties, such as ‘Beauregard,’ ‘Covington,’ and ‘Murasaki.’ Purchasing from certified growers also reduces the risk of introducing diseases or pests to your garden, as their stock is typically inspected and guaranteed to be true to type. While mail-order provides guaranteed variety and quality, the drawbacks include potentially high shipping costs and the risk of slips suffering stress or damage during transit.
Local sources, such as garden centers, agricultural extension offices, and small regional nurseries, provide an alternative for purchasing slips. Local availability is often highly seasonal, typically peaking in late spring when the danger of frost has passed in your area. These local retail outlets usually stock only the most common and regionally adapted varieties. Availability can be sporadic and may sell out quickly, making it less reliable than pre-ordering from a national vendor.
The DIY Alternative: Generating Slips from Tubers
A cost-effective alternative to purchasing slips is to sprout them yourself from a healthy, cured sweet potato tuber. Begin this process approximately six to eight weeks before your anticipated planting date outdoors. One successful method is the soil or sand bed technique, where you half-bury a tuber horizontally in a flat or tray filled with moist potting mix or sand. Another common approach involves suspending a tuber halfway in a jar of water using toothpicks, ensuring the lower half remains submerged.
The tuber must be placed in a very warm environment, ideally with temperatures maintained between 75°F and 85°F, such as on a heat mat or near a sunny window. Sprouts will begin to emerge from the eyes of the potato, and once these shoots reach about six inches in length, they are ready to be separated. Gently twist or cut the slips from the mother potato, taking care to remove any lower leaves that would be buried in the soil. These detached slips can then be placed in a jar of water for a few days to encourage the formation of small, fibrous roots before planting.
Essential Timing and Handling Tips
You should aim to place your order with a specialty grower six to eight weeks before your intended planting window. Upon arrival, your slips may appear wilted or stressed from shipping, which is a normal response to being cut and packaged without soil. The most important step immediately upon receiving them is to remove them from their packaging and place the cut ends in a jar of water for a few days to rehydrate and begin the rooting process.
Do not plant the slips outdoors until the soil temperature consistently registers at least 65°F, and all danger of frost has definitively passed. Sweet potatoes are extremely sensitive to cold, and cool soil conditions will severely stunt their growth and may cause the slips to rot. If your slips arrive before the soil is warm enough, you can “heel them in” by loosely planting them in a small container with moist soil and keeping them in a sheltered, warm location until conditions improve. This brief acclimation period, often called hardening off, allows the delicate slips to adjust to outdoor light and temperature fluctuations before their final placement in the garden bed.