Sweet potatoes are starchy tubers that form underground, just like regular potatoes. They are made from heart-leafed vines, which require a longer growing period (100 to 140 days) as well as warmer soil than regular potatoes.
They were difficult to grow in colder areas of the country until recently. Gardeners can now enjoy this delicious and easy-to-grow crop with the help of short-season sweet potatoes like Georgia Jet and soil warming techniques.
How to plant sweet potatoes?
You simply need to bury leftover potato pieces from the previous year when you plant regular potatoes. Sweet potatoes can be grown from “slips,” which are rooted sprouts taken from mature tubers. You can buy these tender, rooted sprouts by mail or as potted plants at a local garden center. One popular source of slips is The Steele Plant Company.
Sweet potato plants are sensitive and should not be planted outside until the soil is at least 60°F. Nighttime temperatures should not exceed 60°F. Before planting, cover the planting area with black plastic for two weeks to keep the soil warm.
How to care for sweet potatoes?
Cool spring nights should be avoided when planting sweet potato slips. To reduce stress and accelerate early growth, cover the plants with garden fabric for the first three to 4 weeks after they are planted.
Sweet potatoes don’t need that many nutrients so it’s best to not fertilize them at planting time. A surplus of nitrogen will encourage leafy growth, rather than large tubers.
Loose, rich in organic matter, is the best soil for sweet potato plants. Mix some compost in each hole. Next, plant the slips 12-18 inches apart. Cover the stem with soil until the first pair of leaves. You can grow sweet potatoes in Grow Bags as well. Fill the bags with Container Mix and add half a cup of organic granular fertilizer.
To keep the soil warm, mulch the sweet potato with black plastic. It helps prevent them from forming more roots as they grow which reduces the energy needed for tuber formation. If you don’t use plastic, lift the vines occasionally to remove roots from the stem.
How to harvest these starchy tubers?
Regular potato plants’ leaves tend to fall off when it’s ready to be harvested. They will continue to grow until temperatures drop below freezing. Allow them to grow for as long as they can (at least 120 days), but harvest the tubers as soon as the first heavy frost occurs. The sensitive tubers seem to get damaged when temperatures drop. Sweet potatoes are much easier than regular potatoes to dig because they tend to be closer to the stem. The tubers are fragile and easily bruised so be gentle when harvesting them.
After harvesting the sweet potatoes, allow them to air dry for several hours before placing them in a basket or ventilated box with newspaper lining. You should leave the tubers to “cure” at 80-85 degrees for 10-15 days in a warm, dark attic. After curing, the optimal temperature for storage is between 55 and 60 degrees.