How to Grow Sweet Potatoes in Your Garden

The Center for Science in the Public Interest placed sweet potatoes at the top of its list of healthy foods. High in carotenoids, vitamin C, potassium, and fiber, sweet potatoes are also rich in complex carbohydrates, an essential component of a healthy diet.

Because a sweet potato is a tropical plant it needs a long (four-to-five month) growing season to produce good-sized roots, which limits U.S. commercial production to the southern states. With new short-season varieties and modern gardening techniques, however, home gardeners in northern states can grow this nutritious vegetable. In fact, sweet potatoes are now grown in all 50 states.

Sweet Potato Varieties

Beauregard matures in 90 days, making it a good choice for short growing seasons. Bush Porto Rico has short vines, ideal for gardens with limited space. Centennial produces a heavy yield of tapered or cylindrical roots, while Jewell has a narrow, cylindrical shape.

You should be sure to choose cultivars that grow well in your climate. Your local cooperative extension service can tell you which are the best sweet potatoes to grow where you live. You can find the extension offices in your state here.

Sweet Potato Planting and Care

Sweet potatoes are grown from slips, also called transplants. You can grow slips from your own plants, but you are less likely to transmit diseases if you buy disease-free transplants from reputable nurseries.

Sweet potatoes need fertile, well-drained, sandy soil that is slightly acidic (pH 5.6 to 6.5). A soil test will tell you if the soil needs amending to get the right pH and soil fertility. Mounds rows about one foot high to allow space for the roots to develop. Set plants twelve-to-eighteen inches apart in rows three feet apart. To warm the soil, gardeners in northern climates sometimes use black plastic with slits for the plants.

Plant slips in the garden three-to-four weeks after the frost-free date. Plant in late afternoon to protect the roots from the hot sun, and keep the roots moist at all times during the planting process. Set the plants into the ground, but don’t cover the bud. Gently firm the soil around each plant, and water immediately.

For optimal growth and to avoid cracking, sweet potatoes need an even supply of water, at least one inch per week.

Requirements for growing sweet potatoes vary according to location. Your extension service is an excellent source of specific planting and maintenance information.

Sweet Potato Pests and Diseases

Insect and disease problems also vary by location. You can control damage from flea beetles, which affect young plants, by using row covers. To prevent diseases from damaging your sweet potatoes:

· Plant disease-resistant starter plants. Centennial and Jewel, for example, have resistance to the sweet potato flee beetle and southern potato wireworm;

· Rotate crops so sweet potatoes aren’t grown in the same place for at least three years; and

· Inspect plants for rot and lesions and immediately discard diseased plant parts.

Sweet Potato Harvesting

Harvest roots around the time frost kills the vines, which is about 130-170 days from planting for typical long-season cultivars. Or, you can harvest when the roots are small—“baby baker” size.

Sweet potatoes are susceptible to damage during harvest, sunburn if roots are left exposed to the sun, excessive moisture that prevents digging wounds from healing, and skinning and bruising during handling. To prevent injury to delicate freshly dug roots, allow them to dry and cure before washing. If you plan to store your sweet potatoes you must cure them at 80-85 degrees F and 85-90% humidity for about ten days.

For More Information:

Find tips on growing sweet potatoes in different parts of the country from these websites:

Sweet Potato.

Putting Sweet Potatoes in the Garden.

The Sweet Potato.