Here's How To Grow Sweet Potatoes Indoors For A Plentiful Harvest All Year Long

Choosing the absolute best sweet potatoes in grocery stores may soon become unnecessary if you decide to grow them indoors instead. Sweet potatoes thrive when the world around them feels like a long summer afternoon. They crave warmth and sunlight and do not take well to cold temperatures. Outdoor gardeners normally wait for frost to leave the neighborhood before planting, then race the next frost for harvest. Indoors there is no such drama. A sunny window, a bag of loose soil, and a container deep enough for tubers to stretch out is all that stands between a kitchen and a year-round crop.

The thrill starts with slips. Mature sweet potatoes sprout green antler-like shoots when placed halfway in moist soil. Cover the tray to keep humidity high and wait as the sweet potato wakes up and sends up shoots. Once each sprout reaches a few inches in height (about 6 inches or so), it twists free easily. A week in a jar of water gives each slip a respectable set of roots, and from there the little plants are ready for a pot of their own.

Compact potato varieties shine indoors because their vines keep a modest footprint. Vardaman produces shorter, tidier vines, whereas Beauregard works hard in small containers to provide a generous yield. Centennial grows smaller spuds that also suit indoor pots. Regardless of the variety, sunlight remains the fuel. Choosing a spot by a window that faces south can keep a sweet potato in good spirits. Grow lights can also work in a pinch when natural light gives up early in winter. Indoors the season never closes, so the vines simply keep working toward that next harvest.

Once the slips settle into their containers, the job shifts from setup to stewardship. Sweet potatoes enjoy loose, sandy, soil which drains well and invites tubers to expand without running into resistance. A mix of potting soil with peat, compost, or perlite gives the right texture. Watering needs attention, too. Soil must stay moist, not drenched, like a well wrung sponge. A weekly check is enough, though in warmer months the pots might ask for more. When the top inch or two feels dry, it's time for a drink. 

The vines can grow with a kind of gentle restlessness. They trail, curl, and test the edges of their space. Indoors they can be tied along a small trellis or left to drape over the pot like a leafy waterfall. You'll also want to consider adding fertilizer to the plant every three or four weeks. A balanced fertilizer that's low on nitrogen keeps energy directed toward tubers rather than the leaves. Too much nitrogen turns the plant into a showy vine factory with little reward beneath the soil. 

About three to four months after planting, the hidden harvest waits beneath the surface — just make sure to stop watering a week before so the skins can toughen slightly. Then tip the pot onto a tray or plastic sheet and sift through the soil to free each sweet potato. The skin bruises easily, so be gentle to keep it intact. If you like to cook with sweet potatoes and care for the plant properly with these vegetable gardening tips, you'll have a crop that answers to you rather than to the seasons, ready to slip into soups, fries, or slow-roasted dinners the moment the craving whispers.