By Ralph E. Mitchell
Sweet potatoes are surprising plants. Native to tropical America, this tuberous relative of the Morning Glory, is both edible and ornamental. An excellent source of vitamin A, the tubers come in yellow, orange and purple-colored flesh. While this is not the time of year to begin your sweet potatoes, it is a good time to plan for next year.
Sweet potatoes are known to do better in poor, sandy soil and may in fact produce a great deal of vines at the expense of tubers in overly rich, over-fertilized soils. Sweet potatoes are planted in May or June as soon as they are available. Via mail-order, you can purchase rooted cuttings called “slips” that are small, ready-to-grow plants. These slips are about nine inches long and should be set in rows about one-foot apart with around four feet between rows. If grown in containers, use as big a pot as you can get with good drainage. A half-whiskey barrel (or a plastic version) will work fine. Bush-type cultivars such as ‘Vardaman’ work particularly well in small space gardens. As the vines grow, you can make more rooted cuttings to increase your future crop. At this time of year, your sweet potatoes should have a healthy set of vines which are fueling the development of the underground tubers.
Although I really favor white/yellow-fleshed sweet potatoes, some Florida favorite varieties include ‘Centennial’ and ‘Beauregard’ – both orange-fleshed . While seed catalogs offer these, on occasion, you can find them locally as started plants in six or nine unit packs. Some Internet sources also offer many heirlooms and specialty varieties.
Sweet potatoes take up to four months to develop, so do not harvest them too early. Once harvested, place the individual tubers in a dark, warm place for two weeks. This curing allows a portion of the starch to change to sugar. Store cured sweet potatoes in a cool, dry place, but not the refrigerator where temperatures below fifty degrees can produce bad flavors and rots. In addition to the tubers, keep in mind that during the summer, the new tender leaves can be used as greens – double duty!
While sweet potato weevils and whiteflies can be an occasional insect problem, then can be managed when encountered. Rabbits may also sample the leaves – use fences! Otherwise, sweet potatoes are one summer vegetable crop that will grow themselves. Sweet potatoes look good ,too – above and below ground! For more information on all types of vegetables that can be grown during our summer months, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – https://blogs.ifas.ufl.edu/charlotteco/files/2018/03/Plant-Clinics-Schedule.pdf. Ralph E. Mitchell is the Director/Horticulture Agent for the Charlotte County Extension Service. He can be reached at 941-764-4344 or firstname.lastname@example.org.
UF/IFAS Gardening Solutions (2018) – Sweet Potatoes – UF/IFAS Extension Service.
Pak Brown, S., Treadwell, D., Stephens, J. M. & Webb, S. (2018) Florida Vegetable Gardening Guide. The University of Florida, IFAS.