The sweet potato (Ipomoea batatas) is a root vegetable that is native to Central and South America. Usually ready for harvest in about 100 days, the sweet potato is grown from "slips," which are sprouts of the sweet potato plant. You can grow sweet potatoes successfully in your garden only if your region receives at least four frost-free months during the spring and summer. Plant your sweet potato slips in the garden in the spring, when all chance of frost has passed and the soil has warmed to about 60 to 65 degrees Fahrenheit. Choose a planting site that has well-draining soil and receives full sunlight.
Loosen the soil at the planting site to a depth of about 12 inches using a pitchfork or rototiller. Spread a 3-inch layer of organic compost or aged manure onto the soil bed and mix it down into the soil.
Create ridges in your garden by mounding up the soil to about 8 inches high and 12 inches wide. Space the ridges or rows at least 3 feet apart to allow for plenty of growing space.
Plant the sweet potato slips into the ridges so that they're planted down to the first set of leaves with several nodes beneath the soil surface. Space the sweet potato plants about 1 to 1 1/2 feet apart.
Pull any weeds by hand during the first three or four weeks. After the sweet potato plants begin to grow larger and spread, they will naturally choke out any weeds and weeding won't be necessary.
Water your sweet potato plants deeply only during prolonged dry spells or drought. Stop watering the plants about three weeks prior to harvest.
Harvest your sweet potatoes in the late summer or early fall. Dig out the roots carefully with a spade or shovel, starting at the base of the ridge or slightly below. Avoid bruising or cutting into the sweet potatoes.
Set the harvested sweet potatoes on the ground and allow them to dry for two to three hours. Then, place the sweet potatoes in a warm, humid room at around 85 degrees Fahrenheit for two weeks. Store the sweet potatoes afterward in a cool, dark place at about 55 degrees.