Home-Grown Sweet Potatoes (Ipomoea batatas)

Cynthia W. Mueller, Master Gardener, Galveston County, TX
Sweet Potatoes
Home-grown sweet potatoes

The sweet potato Ipomoea batatas is one of the classic Southern vegetables that can be grown in the home garden with ease. Even George Washington grew them! They do prefer good sandy soil but are able to adapt to many different soil types in the garden. There are many varieties to choose from. Slips may be ordered from mail-order supply sources the first year, then fresh slips may be grown from your own sweet potatoes after that.

Some favorite varieties include 'Centennial', an old favorite, and 'Georgia Jets,' planted because of its very fast growth and high yields.

Dr. Larry Ralston, entomologist with the LSU Ag Center, bred up a much more insect-resistant sweet potato in 1987 which was called the 'Beauregard.' This has become the most popular Louisiana sweet potato because of its beautiful eating appearance, with copper colored flesh.

Various white sweet potatoes, with names such as 'Triumph', 'Southern Queen', 'Poplar Root', 'Choker' and 'White Bunch' are usually sweet, but dry. The Mexican or Central American 'Boniato' is an excellent grower for Central Texas, with a normal colored skin but white, slightly sweet flesh that cooks up looking much like Irish potatoes. 'Nancy Hall' is an old fashioned yellowish fleshed potato that is not much on looks but is still being grown. 'O'Henry' has basically a white skin and cream colored insides.

The gardener can also choose sweet potatoes by time to maturity. Water regularly in the absence of rain and fertilize with a balanced fertilizer once a month.

As the season progresses, sweet potato vines can appear to be smothering entire garden plots. If space is at a premium, one solution would be to plant "bush" types, such as 'Porto Rico' or 'Vardaman.' The vines can often be redirected into relatively empty areas of the garden. In order to keep an eye on the spots where the underground tubers are forming, or in order to water successfully, it is sometimes necessary to plant a few sticks or rods in the ground next to the roots of the plants. In the fall at harvest time, digging near the markers will bring up the largest and most developed potatoes. The vines often root here and there along the way and numerous smaller plantlets with tubers may appear. If these are too small to harvest, they may be left in place in the ground. In a mild winter they may survive to repopulate the garden the next spring. Be sure that garden soil is heaped over their tops, because any direct contact of the young tubers with frosty air will cause them to blacken. Otherwise, harvest smaller tubers and bury them in pots of soil to be put away in the garage, shed or other freeze-proof area to produce "slips" for the next year. The containers may be moistened lightly several times through the winter.

when it is time to harvest, do so before the soil temperature drops to less then 50°F to prevent frost blackening. The vines may be frosted partially with the first few cold snaps. At this time, cut these back and dig the sweet potatoes, preferably while soil is dry. Take care not to bruise or cut the tubers.

Sweet potatoes are then cured to allow the skin to heal over, which prevents the entry of disease organisms and ensuing decay. Gardeners can put the sweet potatoes into sheds or garages where there is good air circulation and where the building will be warm enough to facilitate skin healing. Commercial growers plan to keep the sweet potatoes at the temperature of 80 to 90°F, with a relative humidity of 85 to 90 percent. After about two weeks the sweet potatoes will be cured.

Storing them through the winter is most successful in a building where the temperature is well above freezing and the air is dry.

Photo courtesy of Department of Horticulture, Cornell University

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