Sweet Potato Cultivation Methods

Site Selection and Preparation

• Selecting and preparing the growing site is a critical to the cultivation process. Sweet potatoes require well-draining soil with sufficient minerals and nutrients to produce an optimal yield at the end of the year. A soil pH level between 5.5 and 6.5 is best for growing sweet potatoes. Sulfur compounds and limestone mixed with soil alters pH levels. According to a Purdue University publication, the growing area should be prepared a few weeks before planting the slips by digging or plowing the soil to a depth of at least 8 inches. Freshly broken soil forms the ridges and rows. Sweet potatoes are vulnerable to deficiencies, particularly potassium, so fertilizers are often applied to supplement needed nutrients.

Slip Production

• Unlike most vegetable and fruit crops, sweet potatoes are not planted directly as seeds in fields and gardens. Sweet potatoes are transplanted as slips, which are young shoots that emerge from the mature plant’s roots. Healthy, mature roots stored in a starter bed produce slips. According to a Purdue University publication, fill the bed with potting soil or sand, kept moist and heated to 75 or 80 degrees Fahrenheit. Slips can develop in cold frames as well, but emergence is often much slower than in heated beds. A bushel of mature roots produces several thousand slips in the course of multiple bedding sessions.

Planting Slips

• Plant slips as early as possible, particularly in regions with cool climates and shorter growing seasons. They are not cold tolerant and are often planted a few weeks after the danger of frost has passed. Remove slips from the rooting bed after five or six weeks by holding them at the base and firmly pulling them from the mature root. The slips are transplanted into the field or garden with at least 12 inches of room between plants. According to the University of Illinois Extension, sweet potatoes perform well when planted on slightly raised rows that are roughly 8 inches high and several feet apart.

Early Crop Management

• Removing weeds from around the young sweet potato slips avoids competition for nutrients. Once the plants begin maturing, their sprawling vines and leaves are often sufficient to deter weedy plants. Keep the soil around the plants moist but not saturated. Overwatering encourages the growth of soil-borne fungi that harm sweet potato plants. According to the University of Illinois Extension, not watering sweet potatoes during the last month of their growth improves the harvested roots’ quality.