I recently ordered two cultivars of sweet potato slips from George’s Plant Farm in Georgia (tatorman.com). This will give me three different kinds to grow, one here in my cinder block raised bed after I dig my Irish potatoes, one in my raised fire ring bed at Big Momma’s, and one at our school garden in Tyler. I already had an heirloom pass-a-long from Mississippi which I potted up to produce my own slips like my late cousin Ruben next door always did in a washtub at the end of his house. Ruben Smith produced and sold sweet potatoes, mustard greens, and sugar cane, and I loved watching and learning from him.
I grew up attending the Yamboree in Gilmer, Texas, where they celebrated the “yam’s” contribution to the local economy. Unfortunately they don’t produce yams in Gilmer, Texas, or the United States for that matter. What many folks call yams in the South are actually sweet potatoes (Ipomoea batatas). True yams are a tropical root crop not related to sweet potatoes. The African name “yam” came in with enslaved Africans and since sweet potatoes were similar in cultivation and preparation, the name was transferred to them. Sweet potatoes by any name belong in every Texas garden and on every Texas table.
Sweet potatoes are a warm season crop that cannot tolerate frosts or freezes. They can’t even stand cool days or nights. The vining plants thrive on heat, so should be planted well after the last frost. This is generally March/April in the southern half of Texas and April/May in the northern half of the state. Sweet potatoes are planted from “slips” or rooted cuttings which were once available from feed stores but are now mostly obtained from mail order sources or self propagated in pots or a jar of water like I did with the one our pet squirrel Caleb ate years ago (see my very first Arbor Gate bog, archived May 10, 2011). The slips should be planted 12-16 inches apart. The cuttings can actually be planted with or without roots. Generally watered in once, they proceed to root and grow.
Sweet potatoes require at least 8 hours of direct sun each day for maximum yields. They do best in well drained sandy and loamy soils and are best planted in raised beds or rows at least 6-12 inches high. It is ideal to till in several inches of compost or organic matter and incorporate 1 pound of a complete lawn fertilizer (15-5-10, 18-6-12, etc.) per 100 square foot of bed or every 35 feet of row before planting. In smaller plantings use 1 teaspoon per square foot or foot of row or bed. Certainly organic fertilizers can be used; you just have to apply more since the nutrient content is lower. The ideal soil pH for growing sweet potatoes is 5.5-6.5.
Plant sweet potatoes in raised beds or rows 6 inches high, 18 inches wide, and 36 inches apart. Using a trowel, make holes for the slips every 12-16 inches down the row. Place the rooted cuttings in the ground with only the upper leaves above the ground. Water them in with a half strength water soluble fertilizer (Miracle Grow, etc.) before covering them with well cultivated soil. Water them again to eliminate any air pockets.
Sweet potatoes can also be produced in large whiskey barrel sized planters, 30 gallon nursery pots, crown tire planters, or raised beds.
Sweet potatoes have few problems and are easy to grow as long as they have heat and sunshine, and regular irrigation. About 4 weeks after planting, side dress them (sprinkle beside) with a complete garden fertilizer (13-13-13, 10-20-10, etc.) at ½ pound per 35 feet of row. Apply to both sides of the row, work the fertilizer into the surface of the soil, and water lightly.
Sweet potatoes are generally ready to dig in 90-110 days. They don’t actually mature but are dug when they reach a usable size. It’s always best to inspect the base of a few plants to check their size before digging them. If they are too small, leave them longer to grow. When the soil is dry, use a shovel to carefully dig the entire root system. Be careful to not damage the sweet potatoes. Cut the roots away from the plants and allow them to dry for 3-4 hours in the shade before placing them in a warm, humid area to cure for two weeks. Use your garage or shed and place them in containers covered with moist burlap. They should then store for 3 months if kept in a cool (55 degrees) place.
The large, overgrown, and misshapen sweet potatoes can always be used for pies, casseroles, and cut up for roasting.
Recommended sweet potato varieties for Texas include Beauregard, Centennial, and Jewel. I’ve also grown white fleshed ones and used them for summer Irish potatoes. They also come in cream, yellow, orange, red, and deep purple fleshed varieties. My Cajun won’t tolerate anything but orange but I love them all, especially the odd balls. If you want to view the full array of their genetic variability, visit the Sand Hill Preservation website (sandhillpreservaton.com) and click on “sweet potatoes.” I want to grow (and eat) them all! Sweet potatoes originated in Central and South America but are now grown in warm climates worldwide.