Everything You Need to Know About Growing Sweet Potatoes

6 min read

When it comes to nutritious foods, you can’t go wrong adding sweet potatoes to your diet. Not only are sweet potatoes packed with vitamin A, fiber, and protein, you can use the root vegetable to make everything from delicious casseroles to breakfast burritos. The best part? You can easily grow your own sweet potatoes at home.

Keep scrolling for a detailed guide on how to plant and harvest sweet potatoes, plus learn helpful tips on growing them in containers. Keep in mind that a sunny vegetable garden is ideal for them to thrive, and they can take 85 to 120 days to fully mature.

Popular Sweet Potato Varieties

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There’s a variety of sweet potatoes you can choose to grow in your home garden. Note that fast-growing varieties have orange flesh that becomes moist when cooked, but this shouldn’t stop you from buying others with purple, white, or yellow flesh. Here are some common types to consider:

Beauregards: These sweet potatoes have dark-reddish purple skin and take 90 days to mature.Bush Porto Ricos: You’ll have to wait for at least 110 days for these copper-colored sweet potatoes to grow. They’re ideal for small gardens and baking.Centennials: With their carrot-orange flesh, this widely-used variety takes 100 days to mature. They’re also known as America’s most popular sweet potatoes.Georgia Jets: Wait 90 days for this red-skinned variety to grow. They’re fast-growing and have deep orange flesh that’s moist once it’s fully cooked.Stokes: Great for savory dishes, stokes have purple skin and rich purple flesh. They take 120 days to mature and are more nutritious in Vitamin Cthan orange sweet potatoes.Vardamans: Since this variety is a bush type, they have short vines that won’t overwhelm the rest of your crops. This makes them great for small gardens. You’ll notice their blue or purple foliage and reddish-orange flesh.White Yams: Also called the “White Triumph” for their white skin and white flesh, white yams are one of the oldest sweet potato varieties and take 100 days to mature.How to Plant Sweet Potatoes

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Sweet potatoes will grow in poor soil, but deformed roots may develop in heavy clay or long and stringy, sandy dirt. For the ideal environment, create long, wide, 10-inch-high ridges spaced 3½ 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, available at nurseries and mail-order suppliers (store-bought sweet potatoes are often waxed to prevent sprouting). Save a few roots from your crop for planting next year.

About six weeks before it’s time to plant sweet potatoes outdoors in your area (at least three to four weeks after your last spring’s frost), place the roots in a box of moist sand, sawdust, or chopped leaves and keep it in a warm spot (75 to 80 degrees). 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 85 to 120 days and they’re extremely frost-sensitive. Plant them in full sun three to four 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.

How to Grow Sweet Potatoes

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If you’re not using black plastic, mulch the vines two weeks after planting to smother weeds, conserve moisture, and keep the soil loose for root development. Occasionally, lift longer vines to keep them from rooting at the joints, or they will put their energy into forming many undersized tubers at each rooted area rather than ripening the main crop at the base of the plant. Otherwise, handle plants as little as possible to prevent wounds that are vulnerable to disease spores.

If the weather is dry, provide 1 inch of water once a week until two weeks before harvesting, then let the soil dry out a bit. Don’t overwater, or the plants—which can withstand dry spells better than rainy ones—may rot.

When growing sweet potatoes in containers, use one large enough to handle their growth (Herbalist Kendra Meador of Epic Gardening recommends a 15- to 20-gallon container like a half whiskey barrel). Pour four inches of soil into the container (Use a mix with compost, sand, and high-potassium fertilizer), before placing your slips on top. Secure your slips with three more inches of soil.

Common Pests and Diseases

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Southern gardeners are more likely to encounter pest problems than gardeners in Northern areas. Read on to learn how to deal with the most common pests and diseases, and how The Almanac recommends curing them.

Sweet Potato Weevils: These pests are ¼-inch-long insects with wings, dark blue heads, and red-orange bodies. Developing larvae feed on the fleshy roots, while adults generally attack the vines and leaves. They also spread foot rot, which creates enlarging brown to black areas at stem ends and areas near the soil. Use certified disease-resistant slips and practice a four-year crop rotation. Destroy infected plants and their roots, or place in sealed containers and dispose of them with household trash.Black Rot: This results in circular, dark depressions on tubers. Discard infected potatoes, and cure the undamaged roots from the same crop carefully. Don’t confuse this disease with less-serious scurf, which creates small, round and dark spots on tuber surfaces without affecting eating quality.Stem Rot: Also known as wilt, this fungus enters plants injured by insects, careless cultivation, or wind. Even if this disease doesn’t kill the plants, the harvest will be poor. Minimize the chances of disease by planting only healthy slips. Avoid black and stem rot by planting resistant cultivars. Reduce the incidence of dry rot, which mummifies stored potatoes, by keeping the fleshy roots at 55 to 60 degrees.White Rust: This fungus will have chalk-white blisters on the undersides of the leaves. The flowers and stems may also be infected. To rid your sweet potatoes of white rust, destroy the infected plants and try rotating your crops.Whiteflies: As the name suggests, these insects are tiny, white and triangular in shape. They’ll leave a sooty substance on your leaves that’ll have them wilted and stunted. Luckily, you can use a vacuum to remove them or spray them with insecticidal soap.Flea Beetles: These shiny, beetle lookalikes are black, brown, or blue. They appear as tiny dots that leave holes in the leaves. Prevent them from attacking sweet potatoes by using row covers. Mulch heavily to treat and try adding native plants to invite beneficial insects, such as ladybugs. Dill and marigolds are also great companion plants that ward off flea beetles.How to Harvest Sweet Potatoes

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You can harvest as soon as leaves start to yellow, but the longer a crop is left in the ground, the higher the yield and vitamin content. Once frost blackens the vines, however, tubers can quickly rot.

Use a spading fork to dig tubers on a sunny day when the soil is dry. Remember tubers can grow a foot or more from the plant and that any nicks on their tender skin will encourage spoilage. Dry tubers in the sun for several hours, then move them to a well-ventilated spot, and keep them at 85 to 90 degrees for 10 to 15 days. After they are cured, store at around 55 degrees, with a humidity of 75 to 80%. Properly cured and stored sweet potatoes will keep for several months.

Essentials to Grow Sweet PotatoesMiracle-Gro Garden SoilCredit: MiracleGroPlastic SheetingCredit: Frost King

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Mariah Thomas (she/her) is an assistant editor for Good Housekeeping, where she covers home and lifestyle content. Mariah has more than four years of editorial experience, having written for TLC, Apartment Therapy, Women’s Health and Avocado Magazine. She received her master’s degree in journalism at the Craig Newmark Graduate School of Journalism and published her first book, Heart and Soul: Poems of Thoughts and Emotions, in 2019. She’s also the founder of RTF Community, a platform for creatives of color to connect, learn and showcase their work. 

Monique Valeris is the home design director for Good Housekeeping, where she oversees the brand’s home decorating coverage across print and digital. Prior to joining GH in 2020, she was the digital editor at Elle Decor. In her current role, she explores everything from design trends and home tours to lifestyle product recommendations, including writing her monthly column, “What’s in My Cart.”