Sweet potatoes require full sun, well-drained loose fertile soil, and adequate soil moisture. Weed control is needed before vines cover the ground. Provide adequate moisture during dry weather conditions. Do not water during the last three to four weeks before harvest. Rotate sweet potatoes with other vegetables to reduce build up of diseases.
Sweet potato is a tender warm season vegetable that requires along growing season. Sweet potatoes are are started from "slips." Buy slips grown from certified disease-free roots. You can start your own plants by placing several sweet potato roots one inch apart in a hotbed then cover with a thin layer of sand or soil (about 2 inches thick). As the shoots begin to appear, add 1 inch layer of sand. Keep the bed moist and warm (70 - 80 degrees Fahrenheit). Plants are ready for transplanting when they are rooted and 6 to 8 inches high. Plant directly in the garden.
Harvest sweet potatoes in fall before the first frost using spading fork. Be careful not to bruise or damage the roots. The roots need to be cured before storage. Immediately after harvest, let the roots dry on the ground for about 3 hours, cure the roots by putting them in a warm room (85 degrees Fahrenheit, and 85% rlative humidity) for about two weeks and then store in a cool location (55-60 degrees Fahrenheit, 85-90% rlative humidity) for 4-6 months. Sweet potatoes should be handled as little as possible.
Dig the roots immediately if the vines are killed by frost, and cut off the vines from the roots to prevent vine decay spreading to the roots. Use potatoes as soon as possible after they have been stored.
Make ridges about 8 inches high. Set the plants 12 to 18 inches apart in ridges or rows that are 3 to 4 ft apart. Ridged soil tends to warm up much faster in early spring. However, far north where it takes along time for the ground to warm up, some growers and home gardeners cover the ridged soil/beds with black plastic mulch to warm up the soil, holes punched on plastics where plants were set.
Additional pests and problems that may affect this plant:
- Colorado potato beetle
- Potato leafhoppers
- Flea beetle
- Black rot
- Foot rot
- Fusarium wilt
- White rust
- Storage rots
Ornamental sweet potatoes are grown as groundcovers or in containers such as hanging baskets, planters, and in bottles of water.