Sweet potatoes are a nutritious root crop that thrives in warm climates. Unlike standard potatoes, they are not grown from seed or a whole tuber, but from special cuttings called slips. A sweet potato slip is a small vine sprout, often with roots already formed, ready for transplanting. Successful cultivation requires providing specific environmental conditions that mimic the sweet potato’s tropical origins.
Preparing the Soil and Timing
Planting sweet potato slips requires careful attention to environmental conditions to ensure the sensitive sprouts survive and develop into storage roots. Timing is determined by temperature, as this heat-loving crop is intolerant of cold. Slips should only be planted after all danger of frost has passed. The soil temperature must consistently register between 60 and 65 degrees Fahrenheit (15 to 18 degrees Celsius) when measured at a depth of four inches. Planting when temperatures are below 55°F will damage the young plants and inhibit growth.
Proper soil preparation is important, focusing on a loose, well-drained medium that accommodates the expanding roots. Sweet potatoes grow best in a light, sandy loam, since heavy clay soils restrict root development, resulting in misshapen or smaller yields. To optimize drainage and facilitate soil warming, slips should be planted into raised beds or mounds, often called hilling. These hills should be built eight to ten inches high, which allows the soil to heat up faster and gives the developing storage roots ample room to expand.
The Mechanics of Planting Slips
Planting a sweet potato slip must be done with precision to ensure the stem nodes are correctly positioned to form new roots. Before planting, gently remove the lower leaves, leaving only the top two or three intact. This minimizes moisture loss through transpiration and allows the stem to be buried deep enough for optimal root production. The stem contains multiple nodes, which are the points where new roots and sweet potatoes will form.
The planting depth is important, requiring the slip to be set deep enough to cover most of the stem, burying at least four to six inches. The goal is to submerge all potential root-forming nodes, leaving only the small cluster of leaves above the soil line. To position the slip, a small hole or dibble can be used to insert the slip at a slight angle, or horizontally. Ensure the entire buried portion is in contact with the soil. Once placed, the soil must be gently firmed around the stem to eliminate air pockets, which can dry out the developing roots.
Spacing between the slips should be generous to allow for extensive vine growth and proper root development. Within the raised bed or hill, slips are typically spaced 12 to 18 inches apart. If planting in multiple rows, the rows should be spaced three to four feet apart to accommodate the sprawling vines. Wider spacing often results in the production of larger individual sweet potatoes.
Essential Care During Establishment
The period immediately following planting is a delicate establishment phase. Focused attention ensures the slip transitions successfully from a cutting to a self-sufficient plant. The first action after planting is a thorough, deep watering to settle the soil around the buried stem and roots. This initial saturation eliminates remaining air pockets and provides the immediate moisture the stressed plant needs to begin forming new roots.
For the first few days, young slips are vulnerable to intense sunlight and heat, which can cause severe wilting. If the sun is strong or the weather is hot, providing temporary shade or planting on a cloudy afternoon helps reduce transplant shock. Consistent moisture must be maintained for at least the first week after planting, as the newly forming roots are shallow and dry out quickly.
The soil should be kept uniformly moist but not waterlogged, which could lead to rot. This practice is maintained until the slip shows clear signs of establishment, such as new leaf growth or a visible perking up of the foliage. Once established, the plants become more tolerant of drier conditions. However, maintaining consistent moisture for the first 50 to 60 days is important for robust development.