SWEET POTATO
Sweet potato is packed with beta carotene and a delicious, more nutritious alternative to potatoes. While not related to yams, it's often labeled as such in grocery stores.
VarietiEs
Sweet potato comes in orange-, purple-, and white-fleshed varieties. Nancy Hall is an orange variety that grows best in warm regions. Georgia Jet does well in cool regions. And Beauregard grows just about anywhere. For purple sweet potatoes, try Bonita, O’Henry, and Sumor. For white, you’ll want Violetta or All Purple.
WHERE SWEET POTATO THRIVES
Regional compatibility
Although sweet potatoes can be successfully grown in cooler, northern regions of the United States, they do best where the summers are long and hot.
Optimal sOIL & sun
Sweet potatoes like a mildly acidic soil in a well-drained, warm site. Potatoes grown in alkaline or basic soils are more susceptible to disease, and good drainage helps prevent the tubers from rot. They can grow in compact clay soils but will be rough and irregularly shaped rather than uniform in size. These tropical plants prefer about eight hours of full sun a day.
RESILIENCE
These sweet tubers prefer hot, humid weather to a cool, frosty climate and are not particularly drought-tolerant. They also won’t grow well in salty soil.
PLANTING
FROM SHOOTS
The sweet potato equivalent of cuttings are shoots that sprout from a mature potato. You can either buy shoots or sprout them from store-bought tubers. To grow sweet potatoes from other sweet potatoes, clean your tubers and cut them in half. Use toothpicks to suspend the potato piece, cut face down, over a bowl of water, lightly touching the surface. Keep the bowl in a warm place and you’ll soon see shoots growing.
Once the shoots are five inches long, gently snap them off. Place each shoot in another shallow bowl of water so the stem is submerged and the leaf end hangs out of the bowl. Within a few days, you’ll see root hairs growing from the stem. These are slips. Keep them healthy by changing the water daily and discarding the ones that aren’t producing roots or are wilting. The slips are ready to plant when the roots are about an inch long. Choose a warm, sunny site and plant them 12 to 18 inches apart.
There’s an even simpler way to start sweet potatoes: buy some from the grocery story, dig a trench, toss them in, and cover them up with soil. The deeper you plant your tubers, the more sweet potatoes you’ll harvest.
Best time of year to plant
Plant your sweet potatoes in the spring after the weather heats up. Soil that’s about 60 to 85 degrees warm is important for their growth.
COMPANION PLANTS
Good companion plants for sweet potatoes include aromatic herbs like dill and thyme, which help keep away pests. Avoid planting sweet potatoes with squash because both need a lot of room to spread out.
Growing
In warm areas, sweet potatoes grow quickly, within two weeks of planting. Where it’s cool, you can warm up the soil by applying a heavy layer of mulch after planting.
WATERING
Water your sweet potatoes thoroughly and frequently, particularly in the first month of growth. After the vines become long enough to trail, give them an inch of water a week. Avoid overwatering by letting the soil dry out fully or the tubers may rot.
Weeding
Avoid planting sweet potatoes in grassy, or formerly grassy, areas. Grass-loving pests may come back to feast on them.
Fertilizing
Sweet potatoes love soil rich in organic matter. Each spring, dress the top of the soil with a thin layer of compost. Mix in some kelp meal as well to add the potassium sweet potatoes need to flourish.
CHALLENGES
Sweet potatoes may prefer hot and humid regions, but I’ve been growing sweet potatoes in New England for years. It’s only in far northern, less sunny areas, like northern Maine, Alaska, and coastal Washington, where these tubers have trouble growing.
pests & DISEASE
The sweet flesh of these potatoes attracts pests, like the larval form of beetles that feed on the tubers, creating holes and tunnels that can produce rot. Moles, voles, and mice also love to gnaw on tubers. Various caterpillars, like army worms and hornworms, concentrate on the sweet potato foliage. Control them by spraying the leaves with Bt, a natural soil bacteria, or with an insecticidal soap.
Fungal and bacterial rot can damage the roots. Fusarium wilt stunts the vines and creates hard, dark spots on the potatoes. Prevention is the best defense, so plant your tubers in well-drained soil. Make sure never to replant infected tubers or use them to produce slips because disease can be passed along to the next generation.
Harvest
Dig up sweet potato roots in the summer and fall while the weather is still warm. Once the leaves start to wither and turn yellow, your tubers are ready to be harvested. Gently loosen the soil with a pitchfork so you disturb it as little as possible while pulling up the tubers.
STORE
Store sweet potatoes at room temperature, preferably in a dark place.
Preserve
Curing sweet potatoes makes them sweeter because of a chemical process that turns some of the potato starch into sugar. To cure them, keep your potatoes in a warm, humid place for two weeks. Then wrap each sweet potato in newspaper and store it in a cool place (55–60 degrees). Cured sweet potatoes can be stored for up to 10 months.
RECIPES
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