Sweet potato slips are young plant cuttings used to start a new crop. Proper placement is the most important factor for maximizing the harvest. These plants, which are members of the morning glory family, require substantial room to develop storage roots beneath the soil and to spread extensive vines above ground. Providing adequate space prevents competition for nutrients and sunlight, which is necessary for the plant to convert energy into large, well-formed sweet potatoes.
Standard Planting Distances
The standard measurements for planting sweet potato slips are divided into two distinct distances: in-row spacing and row spacing. In-row spacing, the distance between each slip within the same row, is typically recommended to be between 10 and 18 inches. This measurement controls how much subterranean space each developing storage root has to expand without pressing against its neighbor.
Row spacing, measured from the center of one planted row to the center of the next, generally falls between 3 and 4 feet. This wide gap is mandated by the aggressive vining habit of the sweet potato plant, which can easily trail for several feet. The generous space between rows allows the vines to sprawl without creating a dense canopy that shades out neighboring plants or traps excessive humidity, which can encourage disease.
These standard distances ensure that each plant receives sufficient sunlight and air circulation for robust growth. The 10 to 18-inch in-row distance prevents tubers from becoming misshapen or stunted due to crowding while making efficient use of garden space.
Factors Influencing Spacing Adjustments
While standard measurements offer a reliable starting point, gardeners can adjust them based on environmental factors and desired outcomes. Soil fertility influences spacing decisions because highly fertile soil causes vines to grow much more vigorously. In rich soil, plants need more room, so spacing them closer to the 18-inch mark helps prevent dense, tangled growth that can reduce yields.
Conversely, in naturally poorer soil or soil with limited organic material, plants will not grow as large, allowing for slightly closer in-row spacing. Placing slips at the lower end of the range, around 10 to 12 inches apart, maximizes the number of plants in a given area without negatively impacting the yield.
The desired size of the harvested sweet potatoes is another factor that influences spacing. Gardeners aiming for a higher quantity of smaller, uniformly sized tubers often use the tighter 10-to-12-inch spacing. This slight crowding encourages the production of more roots, though they will be smaller overall. If the goal is to produce fewer but much larger sweet potatoes, spacing the slips at the wider end of the range, closer to 16 or 18 inches, gives each storage root the maximum room to expand.
Preparing the Planting Bed
The planting area must be prepared to accept the slips, and two main methods are used: the row method and the hill method. The most common approach is the row or raised bed method, where soil is mounded into long, continuous ridges approximately 8 to 10 inches high. This ridging warms the soil faster in the spring and improves drainage, which benefits root development.
When using the row method, the between-row spacing of 3 to 4 feet is measured from the center of one raised ridge to the center of the adjacent ridge. Slips are then planted along the top of this ridge at the selected in-row distance.
The hill method is an alternative where individual mounds of soil are created for each plant. Slips are typically planted in a cluster on top of the mound, and the overall spacing is measured from the center of one hill to the center of the next. Both methods elevate the planting area, ensuring the developing sweet potatoes have loose, well-drained soil in which to expand.