Have you considered learning how to grow sweet potatoes (Ipomoea batatas)? Beyond the fact that this tasty root vegetable is incredibly nutritious and versatile, sweet potato vines are popular decorative plants that look great in just about any garden or planter. So, whether you’re in it for the nutritional value or in it for its good looks, growing sweet potatoes is a great way to get your hands dirty.
How to Make Sweet Potato Slips
Unlike most other garden vegetables, sweet potatoes (also often mistakenly called yams) are not grown from seeds; they’re grown from rooted plants called slips. Generally, gardeners order a dozen or so slips from a supplier and then plant the slips in their gardens when the time is right (like you would with any transplant) or make their own.
To make your own slips, just take a few sweet potatoes, cut them in halves, and then place or partially submerge the pieces in water in a well-lit area. (Some people use toothpicks to prop up the tuber ends and others just place the tubers in standing water. Either way works.) In a few weeks, roots will sprout from the bottom, leaves will sprout from the top, and you’ll be well on your way to growing slips you can plant.
How to Plant Sweet Potatoes
Once they’ve got enough roots, the slips can be planted directly in the ground. But, if you’ve ordered slips and they arrive early before it’s warm enough outside to plant them, you can plant slips in containers for a few weeks (just be sure to keep them in a sunny space indoors until the weather is right).
When planting sweet potato slips:
- Space the slips 14″ – 18″ inches apart.
- Transplant or plant slips outside 3 – 4 weeks after the last frost.
- Plant slips in loose, well-draining soil that gets at least 8 hours of sun a day. (Note: It is important that your soil be loose. If necessary, work the soil with a trowel or other gardening tool to loosen it up before planting your slips.)
- Plant each slip so that about half of the “bottom” (the rooted end) is buried in the dirt and the “top” (the end the leaves grow from) is above the dirt.
Growing Sweet Potatoes
Growing sweet potatoes really doesn’t require much in terms of elbow grease or maintenance since they don’t need very nutrient-rich soil. (So, unless your soil is particularly overworked and has been depleted of key macronutrients, you rarely need to worry about fertilizing.) For the most part, managing a productive crop just means controlling pests and controlling weeds. When weeding, however, be sure to handle plants gently and to carefully lift vines when looking for hidden problem spots. One potential issue: They can be sensitive to cold soil. As such, be sure to plant slips when there’s no chance of frost.
Sweet potatoes can be harvested whenever they reach usable size (which, depending on cultivar and season, can be anywhere from 3 to almost 5 months after planting). As a visual indicator for when your taters are ready for plucking, look for dry, brown foliage.
To harvest, cut or move vines out of the way, then gently lift the roots out of the ground by carefully probing the ground with a trowel or spade. The skins and flesh bruise easily, so be sure to move slowly and gently.
To cure sweet potato roots, let them dry in the sun for a few hours (minimum 3, up to 24). Then, once they are thoroughly dry, store them for 10 days at about 80° – 85°F with relatively high humidity (85 – 90%). Once both of these curing stages are complete, your sweet potatoes can be stored indoors for a good 6 months.
- Insect predation. Not only are sweet potatoes vulnerable to infestation from common garden pests like aphids and flea beetles, in some climates they’re particularly vulnerable to sweet potato weevils. Sweet potato weevils are particularly damaging, so it’s important to buy sweet potato slips that are weevil-free.
- Plant diseases. Sweet potato plants can fall prey to any number of wilts, rots and mold issues. The best way to keep your plants disease-free is to make sure the soil drains adequately (to prevent various rots), to keep pH levels below 7.0 (to prevent plants from becoming distressed and more vulnerable to disease), and to use only disease-free starter plants (to prevent importing diseases).
- Damage during harvesting season. Just when you think they’re past the danger zone, sweet potato plants can still be permanently damaged by cold temperatures, excessive moisture, and accidental skinning and bruising. To minimize damage during harvesting season, don’t delay harvesting past the first frost, and be gentle when digging up plants.
For more information on planting sweet potatoes in your garden, here’s an excellent informational sheet put together by Purdue University. Otherwise, for more in-depth information on keeping a productive garden, check out the Gardening Guides page for growing tips and more.