How to Grow Sweet Potatoes
About Sweet Potatoes
This abundant, warm weather crop should be a staple in your garden. Its bright, sweet flesh brings the sunshine of summer to your winter soups, stews, and roasts, and it’s great fun to grow.
Sweet potatoes are not even remotely related to the standard nightshade potato. In fact, sweet potatoes are in the morning glory family and a worthwhile addition to the list of tropical crops we love to grow in the summertime.
This traditionally southern crop needs a fairly long growing season (at least four months), but once established, is heat and drought tolerant.
Sweet Potato Slips
If you want to grow some sweet potatoes and pre-order them from us, you may be a little surprised by what we send you. Sweet potatoes are grown from what we call slips. This is a sprout that comes off the sweet potato and is replanted in the ground. So we’re actually sending you live plants!
From the moment the slips are plucked from the field, it is a race to get them into your garden. At Sow True, this means everyone drops what they're doing and heads to the warehouse to count slips and roll them into a damp and nutrient rich soil mixture. From here, we send them out as quickly as we can! You’ll want to open the box containing your sweet potato slips as soon as it arrives, and get those slips in the ground as soon as possible.
Sweet potatoes are also surprisingly resilient. Chris Smith, of the Utopian Seed Project, once did a test on some slips that had lost all their leaves (the ones we don't sell). He planted some in a pot with damp soil and within a couple of weeks, they were sprouting new leaves and looking healthy and green! We like to joke that sweet potatoes are a dramatic bunch, feigning death when they're really full of life. Once you've planted them in your garden, it's almost guaranteed they'll droop and try to convince you they're dead or dying. Don't panic - keep them well watered and they'll perk up in a week or so!
Recommended Sweet Potato Varieties
This delicious and classic variety is your quintessential sweet potato. Beautiful red skin and bright orange flesh makes this crop a stunner on the dinner table. This variety is super easy to grow and produces reliably - it’s perfect for beginners! If you’re looking to try your hand at growing sweet potatoes, this is the one for you!
This popular Japanese sweet potato has the characteristic white flesh and purple skin found in many Japanese varieties. This type has good yields and evenly shaped tubers. Japanese types tend to have a drier consistency than orange sweet potatoes, making their texture more akin to a standard potato when cooked.
This is for the growers who love a story. An heirloom variety so beloved a parade was once held in its honor. The Nancy Hall boasts a rich yellow coloring with a nice, firm texture.
She’s a looker! This new-to-us variety has gorgeous burgundy skin with deep, red to orange flesh. Bakes nicely with a texture on the firmer side.
One of the most popular varieties to plant in North Carolina, for sure. This one has gorgeous rose colored skin and moist orange flesh.
Last, but certainly not least is this perfect white potato, though it still packs the sweetness. With heavy yields and creamy flesh, this is not a variety you’ll want to skip this year.
Not sure which one to pick? Try our sweet potato sampler! We’ll send you a few slips of three different varieties (it’s a surprise) and you get to decide which one you like best after a good old fashioned taste test.
Planting Sweet Potatoes
Slips are essentially the sprouts of sweet potatoes that, once planted in the ground, will vine out and produce a cluster of sweet potatoes around the original slip!
Where to Plant Sweet Potatoes
Sweet potatoes can tolerate moist soils, they aren’t a picky bunch. The most important thing to consider is how much sun your plot is getting. Sweet potatoes, being tropical, require full sun. This means 8 to 10 hours a day of sunlight.
If you have very heavy clay and water logged soils, you may consider amending with plenty of compost and perhaps some sand as deep as 8-10 inches. Sweet potatoes draw the line at heavy, wet soils as that can stunt tuber development and cause rot.
Growing your sweet potatoes in a raised bed can help you avoid these problems! Raised beds can be easily amended and water tends to drain faster.
When to Plant Sweet Potatoes
Sweet potatoes should be planted three to four weeks after your last frost, well into summer. If you live in a colder growing zone and your growing season doesn’t allow for that much time, plant your slips around your frost date and keep a close eye on temperatures. Consider utilizing row cover (or plastic milk jugs) to cover your slips when temperatures drop below 55 degrees.
How to Plant Sweet Potatoes
Plant your slips 3 to 4 inches deep - up to the leaves and bury most of the stem. Keep your slips 12 to 18 inches apart (they spread out - a lot) with 3 to 4 feet between rows!
Growing Sweet Potatoes
Once planted, give your slips a good soaking. Water every day for about a week and then every few days until they get established.
Maintaining your Sweet Potato Crop
They can be slow starters and they don’t like to compete with weeds so until the vines fill in the space, gently cultivate the top layer of soil around the slips to avoid letting competition get a foothold.
Occasionally you may lift the long vines to prevent advantageous rooting at their nodes (this will take energy away from tuber development and result in a lower yield). Some folks even cut back the vines which encourages the plant to work harder at developing tubers.
Fertilizing sweet potatoes tends to produce more foliage than tubers so don’t bother! Once established, sweet potatoes are drought tolerant but they will produce more if well watered during the bulk of the growing period.
Preventing Pests & Diseases
Wireworms and root-knot nematodes are the biggest problems for sweet potatoes in home gardens. Avoid many diseases by choosing disease resistant varieties, using certified disease free slips (like ours!), and rotating their location from year to year. Mice and voles can also be a problem - so be on the lookout!
How to Harvest Sweet Potatoes
Different varieties will have slightly different days to maturity, so be sure to check your variety’s specifics! If you can keep track of the day you planted them, you’ll know when they should be ready. The roots will continue to grow until a hard frost kills the vines. Just be sure to harvest the tubers before then.
Be sure to dig carefully. Any damage to the skin can invite rot, making them hard to store. Push a shovel in about 10 inches away from the stem of the vine and lift. You’ll probably find a variety of sizes per plant. Lay them in the sun to dry out and gently brush off any excess soil. Any injured roots (it happens) should be eaten first! Don’t store injured roots, as it invites rot.
How to Store Sweet Potatoes
Once dug, cure them for two weeks in a high humidity and high heat location for four to ten days. An attic or barn works nicely for this, just choose a location with good ventilation. Flavor and storage quality improves with curing by converting the starches to sugars! Once cured, they should be stored in a cool, dry place like a basement with low humidity. This way they will last several months.
Sweet potatoes are an amazing and nutritious crop. They’re great for beginners and offer a high reward with minimal effort! If you haven’t tried them yet, consider including them in your crop plan this year.
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Article Written by: Hannah Gibbons |
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About the Author: Hannah Gibbons, an employee at Sow True Seed since 2020, has nearly a decade of experience in the agricultural industry. Their passion for environmental education and regenerative agriculture has been the cornerstone of their work, aimed at making gardening accessible to all. |