Sweet potatoes thrive in the heat and humidity of Florida, making them an excellent crop for the state’s long growing season. Successful cultivation depends on adapting to Florida’s unique environment, particularly its sandy soils and intense pest pressure. By selecting the right varieties and following specific cultural practices, gardeners can enjoy a bountiful harvest of these warm-weather roots. Careful planning of planting material and soil preparation is necessary for success.
Selecting Varieties and Planting Slips
Sweet potatoes are grown from cuttings known as slips, which are small vine sprouts taken from a mature sweet potato. Planting certified, disease-free slips helps avoid pests and diseases from the start. Planting should commence in late spring or early summer, after the final frost has passed and the soil temperature consistently reaches at least 65°F. This timing ensures the young plants have the four or more frost-free months required to produce mature roots.
Varieties proven to perform well under Florida’s conditions include ‘Beauregard’ and ‘Centennial,’ both known for high yields and adaptability to heat. For gardeners with less space, the ‘Vardaman’ variety offers a compact, bush-type growth habit. Slips should be spaced approximately 12 to 18 inches apart in rows that are 36 inches apart. The base of the slip, including several nodes, should be buried four to six inches deep, with the top leaves remaining above the soil line.
Preparing Florida Soil and Fertilization
Florida’s native soil is often sandy, draining quickly and typically low in organic matter and nutrients. While rapid drainage benefits root formation, the soil must be amended to improve moisture retention and fertility. Incorporating organic materials such as compost, aged manure, or coconut coir before planting helps build up the sandy composition. The ideal soil reaction for sweet potatoes is slightly acidic, with an optimal pH range of 5.8 to 6.5.
Sweet potatoes have a low requirement for nitrogen compared to other vegetables, and excessive application should be avoided. Too much nitrogen encourages extensive vine growth at the expense of root development, resulting in small or misshapen tubers. The crop demands high levels of potassium, which is important for cell elongation and high-quality root formation. A fertilization strategy focused on sufficient phosphorus and potassium, with only a light application of nitrogen at planting, directs the plant’s energy toward producing roots.
Managing Pests and Common Diseases
Sweet potatoes in Florida face pressure from the Sweet Potato Weevil and Root-Knot Nematodes, requiring preventative cultural controls. The Sweet Potato Weevil is the most damaging pest; its larvae tunnel into the roots, making them unmarketable due to a bitter taste. Sanitation, which involves removing and destroying all crop residue and volunteer plants immediately after harvest, eliminates overwintering sites.
During the growing season, “hilling” or “dirting” the plants—mounding soil over the base of the vines—prevents female weevils from laying eggs directly on the developing roots. Pheromone-baited traps can be placed near the planting area to monitor and reduce the adult male weevil population. Root-Knot Nematodes, microscopic worms abundant in sandy soil, cause galls on the roots, leading to stunted growth and reduced yields.
Management for nematodes relies on selecting resistant varieties, such as ‘Evangeline’ or ‘Jewel,’ and practicing multi-year crop rotation with non-host plants. Soil solarization utilizes Florida’s intense sun to suppress nematode populations. This process involves covering moist soil with clear plastic during the hottest summer months for at least six weeks. Fungal issues, such as Fusarium wilt and Black Rot, are prevalent due to high humidity and can be mitigated by ensuring excellent soil drainage and using certified, disease-free slips.
Harvesting and Curing the Crop
Sweet potatoes require a growing period of 90 to 120 days from planting until the roots are ready for harvest. A visual cue for maturity is the yellowing of the vines, signaling that the plants are shifting energy away from foliage production. Harvesting must occur before the first hard frost, as cold temperatures can damage the roots and compromise their storage life.
The digging process must be done with care to avoid bruising or cutting the thin skin, which can introduce pathogens that cause storage rot. Use a pitchfork or shovel, digging a wide circle about 18 inches away from the center of the plant to gently loosen the soil before lifting the roots. After harvesting, the roots must undergo a two-step post-harvest process to maximize flavor and storage duration.
The first step is curing, which involves holding the sweet potatoes at a high temperature, ideally between 80°F and 85°F, with 80 to 95 percent humidity for four to fourteen days. This warm, moist environment promotes the healing of minor skin wounds and initiates the enzymatic conversion of starches into sugars, developing the characteristic sweetness. Following curing, the roots should be moved to a cooler, dry location, storing optimally at 55°F to 60°F for long-term preservation.