How to Grow Sweet Potato in Containers?
You want to grow sweet potatoes, but you’re worried your garden is too small?
It doesn’t really matter how small your garden is, you can successfully grow sweet potatoes in a container or tub too.
Sweet potatoes are available in an edible form that produces large tuberous roots with less attractive foliage, and a form that’s not cultivated for human consumption but more as an ornamental trailing plant, with small tuberous roots that aren’t as tasty as the real thing.
Whichever variety you want to cultivate, both are suitable to be grown in pots and containers and both have the same growing requirements that I discuss below.
How to Propagate Sweet Potatoes?
You can propagate sweet potatoes from tubers, or you can buy sweet potato “slips” (sprouts from tubers) from garden centers directly.
This last option is certainly faster and more convenient, but if you have a sweet potato variety that you’d enjoy harvesting at home, propagating from tubers isn’t hard at all, it only takes a bit more time.
If your garden center does not carry sweet potato slips, you can sprout your own sweet potatoes at home by placing them into water.
Find the middle of each tuber and stick at least three toothpicks (½-1 inches in) around the circumference of the tuber. Make sure they’re spaced out.
Find a jar that can hold the tuber, fill with water, and place the tuber into the jar so that the toothpicks hold the tuber from falling into the jar completely.
The bottom half of the sweet potato should be immersed in water, the other half stays out of the water. Preferably, you should use organic tubers and the water should be chlorine-free.
The jar with the tubers should be kept in a sunny windowsill and the water should be replaced every 2 or 3 days. You should see sprouts emerging within 4-6 weeks from the top half of the tuber.
When sprouts are large enough that they can be separated into individual slips, they should be moved to a bowl with shallow water until they grow roots.
Some slips may have already formed some rudimentary roots but continue to grow these roots in a shallow bowl, so they become strong enough to plant.
When the roots are about 1 inch long and the sprouts have several leaves, it’s time to place the slips into potting soil in seedling containers that have good drainage.
Sweet Potato Pot & Soil Requirements
If the sweet potato slips are developing well and have started growing more vigorously, you can either transfer them in their own large buckets or tubs, if you’re growing the edible type to allow room for tubers to develop.
If you’re growing ornamental sweet potatoes, you can put them in mixed containers with other plants or their own container, but edible ones should have plenty of room to expand, so make sure you put those in spacious containers.
Ornamental sweet potato plants should be repotted in a larger container if they grow rapidly and become rootbound. You can even prune the roots to make more room for them.
I avoid metal or plastic pots because of their water-retaining capacity, but I’ve seen people successfully use plastic containers without issues.
Just make sure there are plenty of drainage holes on the bottom and the soil is suitable for sweet potatoes.
Although much heavier, I prefer clay pots to plastic or metal. These soak up moisture much better and reduce the chances of rotting. Wooden barrels are also a great option.
As for the soil type, sweet potatoes prefer well-draining soil. Sandy soils work great but do add some compost to the soil to enrich it.
Sweet Potato Watering
Sweet potatoes should not be overwatered. They prefer the soil to be slightly dry rather than too wet. A bit of moistness is acceptable, but don’t allow the soil to stay constantly wet.
If you’re growing established sweet potato plants outside, depending on how much rainfall there is, you may need to water them about once every week or not at all, unless there’s no rainfall in your area.
Do a finger dip test by sticking your finger into the soil up to the second knuckle. If the soil is moist, don’t water. Water only when it feels dry at your fingertip.
Sweet Potato Light Requirements
Sweet potatoes love sunny spots both indoors and out. Full sun to partial shade is the range tolerated, so you can experiment and see how your sweet potato fares in full sun compared to partial shade.
Mine are out in the garden in full sun and they seem to be really enjoying it.
Sweet Potato Temperature
Sweet potatoes are warmth-loving plants that don’t tolerate freezing temperatures, therefore, if you’re keeping them outdoors, make sure to take them back inside when temperatures are approaching freezing levels. You can move them outside, once temperatures reach 65 F.
Sweet Potato Fertilizing
Sweet potato vines or edible sweet potato plants need fertilizing for best results. My approach is to mix a slow release fertilizer into the soil when I plant them in their final containers.
I don’t add any additional fertilizer, but I make sure that the soil has compost in it to provide plenty of nutrients during the long growing season.
Harvesting Sweet Potatoes
Sweet potatoes that are container-grown can be harvested after about 150 days. It’s best to harvest them before the first frost sets in.
After harvesting, it’s best to cure the harvested tubers in a warm and dry place for 10-14 days. After curing, store them in a cold and dry place.
There are some technicalities with cultivating sweet potatoes in containers when it comes to their propagation, If you get slips from a garden center, your becomes easier, but propagating from tubers isn’t difficult either, it’ll only take longer.
Sweet potatoes, whether the ornamental or edible kind, are otherwise undemanding and you can grow them easily, especially if they’re given warmth and sun.
Make sure you understand the watering requirements of these plants to avoid overwatering and related issues.