(Backyard Gardener - Photo Illustration - MetroCreativeConnection)

Hello, Mid-Ohio Valley farmers and gardeners. Still enjoying wonderful weather in May. It is a busy time of year with graduations and schools finishing up for summer break. Congratulations to all of our graduates. My niece, Marlee Stollar, just graduated from The Ohio State University with her master’s degree in agriculture communications. Way to go girl.

Gardening season is in full swing as we transplant tomatoes and peppers and direct seed squash and sweet corn. It is always a good idea to space out sweet corn plantings, so it is not all ready to harvest at the same time. Keep in mind plant spacing to get good sun and airflow, especially with tomatoes and peppers. Although they need trellised, pole beans are very good yielders for a successful garden. If you can keep up once they start producing.

If you have the room, Sweet Potatoes (Ipomea batatas) are fun to grow, heavy yielders and highly nutritious. They are high in fiber and in vitamins A and C, making them a great addition to the vegetable garden.

One baked sweet potato (about 3 1/2 ounces) contains only 141 calories (this does not include the butter, which makes a baked sweet potato taste great). They are also a great source of the anti-oxidant beta-carotene.

A few interesting facts. The sweet potato is the official state vegetable of North Carolina, due to their sandy soils being an ideal place to grow this root crop. In Japan, sweet potato juice is fermented to produce an alcoholic beverage called “shochu”. During the American Revolutionary War, sweet potatoes were a source of food for colonial troops.

The sweet potato is a true tropical plant. They are a member of the morning glory family, unrelated to the Irish potato which is a nightshade. They have a tuberous root where Irish potatoes are not roots but specialized underground storage stems called “tubers.”

Sweet potato is a warm-season crop that should not be planted until well after the last chance of frost in the spring here in West Virginia. The soil temperature should be above 65F before planting.

Sweet potatoes are produced from plants or sprouts called “slips” produced from the roots of the previous season’s crop and from vine cuttings. You can grow your own slips, but many gardeners prefer to buy slips from a reputable nursery. If you need assistance, contact the office and we can refer some.

It is cool to produce your own transplants or slips by bedding “seed” potatoes you bought or saved from last year’s crop. Pay attention to flesh, skin color, shape and freedom from disease and insects with potatoes you select to grow slips.

To produce your own slips place sweet potato roots on their sides in trays of soil six to eight weeks before you want to transplant them outside. Cover the roots with 2 inches of moist sand and keep the soil in the trays between 75-80 degrees F. When the sprouts are 4-6 inches long, remove them with a twisting tug. Sprouts can be planted directly into well-prepared gardens or raised beds. One seed potato can produce 10-20 plants from several cuttings.

Take heed, sweet potatoes require a long growing season, from 90-150 days. They also require a deep, workable soil. Tight clay soils like we have in West Virginia may produce misshapen potatoes, so work the soil and add amendments like compost or manure to loosen the soil up.

Plants (slips) are planted three to four nodes deep (3 to 4 inches deep), 9 to 18 inches between plants in rows 36 to 48 inches apart. A node is a bump or swelling on the slip where a leaf was attached. Orientation of the slips is not crucial because slips can be planted upside down and still will produce sweet potatoes.

Sweet potatoes should be planted on ridges or raised beds (6 to 9 inches high). Raised beds aid in root development and improve soil drainage and aeration. Sweet potatoes do not tolerate waterlogged soils. Sweet potatoes tolerate acidic soils and the pH can be 5.0 to 6.5 for successful growth.

Another good tip. Transplanting conditions are important for success. If poorly rooted slips are planted in sunny, hot conditions, a large number may desiccate and die before roots can establish. It’s best to wait until overcast conditions, and to make sure to water slips in immediately after planting.

Let’s talk varieties. Popular orange flesh varieties include Beauregard, Covington, Jewel, Georgia Jet, and Porto Rico. These vary in root size, uniformity, and days to maturity. Their skin and flesh color vary slightly as well. Bonita, White Hamon, and O’Henry have cream-colored flesh. Japanese purple have purple skin and white flesh. All-purple varieties have purple skin and purple flesh.

Beauregard is a standard for gardeners in the Mid-Ohio Valley. Covington is also a good improved variety and fast becoming the standard crop in the number one sweet potato producing state, North Carolina.

Sweet potato production is not perfect. Deer love sweet potato foliage, and will browse it to the ground. While this won’t kill the plants, it will reduce yields significantly. Be careful with fertilization. Overuse of nitrogen with sweet potato plants produce just foliage and poor root development. Weeds are perhaps the biggest issue when growing sweet potatoes as the vines spread rapidly over the garden.

Wireworm and root-knot nematodes seem to be the biggest problems for home gardeners. However, many insect and disease problems can be avoided by choosing disease resistant varieties and using sound cultural gardening practices. Crop rotation with a vegetable in another family can help with nematode and soil disease prevention.

Sweet potatoes can be harvested any time after the hills have produced usable potatoes, usually 90-120 days after transplanting varieties. They should be dug as late as possible in the fall, but before a hard freeze. The vines can tolerate a light frost, so it can be helpful to mow and remove vines before digging, to provide easier access to the roots.

Most of the sizing takes place in the last two to three weeks, so keep close check on the size to schedule harvest before the potatoes become too large. Too much soil moisture at this time, however, may cause root rotting before harvest or cracking open of potatoes after harvest.

When harvesting, handle sweet potatoes with care to prevent bruising. They are more fragile than the Irish potato due to their thin skin. After digging, potatoes should be “cured” by placing them in a warm (80-85F) place for four to seven days. This heals any wounds on their skins and increases storage life.

Do not store them in the refrigerator. The roots are easily damaged by temperatures lower than 50F. Sweet potatoes should be stored in bins in moderately warm (55-60F) and humid conditions in a cool, dry place. Contact me at the Wood County WVU Extension Office 304-424-1960 or e-mail me at jj.barrett@mail.wvu.edu with questions. Good Luck and Happy Gardening!