In the garden, on a trellis, or in a container, sweet potatoes are a beautiful plant—delicious tubers in the fall are an added bonus to the lovely foliage and flowers.
Sweet potatoes grow well in a sunny vegetable garden, but you can also grow them in other parts of your home landscape. Try them as a temporary groundcover or a trailing houseplant. In a patio planter, a sweet potato vine will form a beautiful foliage plant that you can harvest roots from in fall.
Sweet potato flesh is classified as moist or dry. Moist, deep orange types are sometimes called yams; the most popular varieties for home gardens are moist types, including 'Centennial' and 'Georgia Jet'. Sweet potatoes are grown worldwide, from tropical regions to temperate climates. This warm-weather crop is remarkably nutritious and versatile. Each fleshy root is rich in vitamins A and C, along with many important minerals. Use them raw, boiled, or baked, in soups, casseroles, desserts, breads, or stir-fries—and don't forget to try some homemade sweet potato fries!
Sweet potatoes will grow in poor soil, but roots may be deformed in heavy clay or long and stringy in sandy soil. To create the perfect environment, build long, wide, 10-inch-high ridges spaced 3 1/2 feet apart. (A 10-foot row will produce 8 to 10 pounds of potatoes.) Work in plenty of compost, avoiding nitrogen-rich fertilizers that produce lush vines and stunted tubes. In the North, cover the raised rows with black plastic to keep the soil warm and promote strong growth.
It's best to plant root sprouts, called slips, which are available from nurseries and mail-order suppliers. Or you can grow your own, by saving a few roots from your previous crop or by buying untreated roots (store-bought sweet potatoes are often waxed to prevent sprouting). About six weeks before it's time to plant sweet potatoes outdoors in your area, place the roots in a box of moist sand, sawdust, or chopped leaves in a warm spot (75º to 80ºF). Shoots will sprout, and when they reach 6 to 9 inches long, cut them off the root. Remove and dispose of the bottom inch from each slip, as that portion sometimes harbors disease organisms.
Sweet potatoes mature in 90 to 170 days and are extremely frost sensitive. Plant in full sun 3 to 4 weeks after the last frost when the soil has warmed. Make holes 6 inches deep and 12 inches apart. Bury slips up to the top leaves, press the soil down gently but firmly, and water well.