The Sweetest Potato

Image Gallery Sweet potatoes come in a wide range of colors and sizes. DAVID CAVAGNARO

Sweet potatoes are productive and easy to grow, have few pests, tolerate drought, and a good harvest can last all winter — plus, they’re fun! The vines’ growth rate is fast and furious, and the reason for such luxuriance becomes clear in autumn when the roots are dug. All that photosynthesizing foliage fattens a fine crop of roots.

Short season varieties have extended the sweet potato’s growing range significantly northward, even into Canada. “Word is getting out … garden centers are now stocking plants regularly, while market growers and community supported agriculture (CSA) participants tell me sweets have become established as customer favorites,” says Greg Wingate, owner of Mapple Farm in Weldon, New Brunswick, Canada, a certified organic supplier of sweet potato plants. “This was unheard of two decades ago!”

Sweet potatoes have a lot to offer nutritionally: They’re loaded with vitamin A and beta carotene, plus healthy amounts of vitamins C, B and E, as well as potassium. They are also a good source of fiber and complex carbohydrates. Like most vegetables, they contain no fat or cholesterol, and a medium-size sweet potato has only about 100 calories.

In the kitchen, sweet potatoes assume varied roles as appetizers, soups, side dishes and desserts with equal panache (see “Candied Sweet Potatoes”). Bake them in their skin, or try them sliced, seasoned with olive oil and herbs, then grilled for just a few minutes per side. You can even eat sweet potato leaves like spinach. Ken Pecota, a sweet potato researcher at North Carolina State University, says people usually cook the greens, using 6 to 10 inches of the tips of vines, when they are relatively tender.

SELECTING THE RIGHT VARIETY

Sweet potato varieties differ in skin color (yellow, orange, red, purple or cream); flesh color (white, yellow, reddish or orange); texture (soft and moist, or dry and firm); shape (blocky to tapered); and flavor (mild to very sweet). The moist, orange-fleshed types are most popular in the United States, although other types are being grown in increasing quantities to satisfy ethnic food markets.

“The Asian markets prefer a purple-skinned, cream-fleshed, smooth-textured, somewhat dry type that is very sweet when baked,” Pecota says. Hispanic markets tend to favor dry, white-fleshed types that are not sweet.

Heirloom varieties also are finding their way to farmers markets and specialty stores. Mike Cox of White Oak Point Farm in Prince Frederick, Md., who grows about an acre of sweet potatoes for local sale, prefers the white-fleshed ‘O’ Henry.’ To introduce his customers to the super sweet, sometimes cantaloupe-sized roots, he tosses one in with their purchase of orange sweet potatoes. “Once they try them, I can’t seem to grow enough,” he says.