Growing Sweet Potatoes in Small Gardens

Think you can’t grow sweet potatoes in a small garden? Think again! My sister and I have harvested as much as 120 pounds of sweet potatoes from a modest 50-square-foot raised garden bed.

I prefer to grow the bush varieties of sweet potatoes, as the vines of standard varieties grow up to 16 feet long and can take over a small garden all by themselves! I’ve heard that a few people will actually trellis their sweet potato vines to keep the vines out of the way, but I haven’t needed to do that with my bush types. The vines of bush types usually stay less than 5 feet long.

I’ve only grown sweet potatoes a few times, so I’m still learning the ins and outs of how to grow and harvest them. They grow best in loose, deep, well-drained soil that is not too rich in nitrogen. Sweet potatoes are a hot weather crop, and shouldn’t be planted until your soil is quite warm – usually 2-4 weeks after your last spring frost. I don’t plant mine until June 1st, which gives me time to grow and harvest a spring crop of early-maturing vegetables in the garden bed before I plant my sweet potatoes.

Sweet potatoes are a low maintenance plant. Once we plant them, we keep them weeded, mulched and watered, and let them grow. It’s important to not let the soil dry out too much. If there is a heavy rain after a long dry period, many of your tubers could split from absorbing the water too quickly. (Guess how I learned that!)

Another advantage of this vegetable is that their leaves are edible – unlike the poisonous Irish potato leaves. Sweet potato plants provide abundant cooking greens during the hottest season of the year. Just don’t remove too many leaves from any one plant at one time, if you want a large harvest of the tubers.

If you live in an area with a short growing season, look for varieties that mature quickly. Sweet potato plants grow much faster in hot weather and warm soil, so if you live in an area with cooler summers, it may be worth covering your plants with row cover, to give them a warmer, more protected environment to grow in.

I don’t want to risk having our sweet potatoes damaged by frost, so we schedule our harvest for the first week of October, before the date of our average first fall frost.

To make the harvesting easier, we cut off all the vines and removed them from the bed. The remaining large tubers had grown several inches above the soil, as well as deep into the soil.

We used a spading fork to carefully lift the tubers from the soil.  This is much easier to do with larger raised beds. One year, I grew sweet potatoes in small 3′x4′ 8-inch-high beds. There was no room to use a spading fork – so we had to dig them out with a trowel! This proved very difficult, as the tubers grew very deep, down into the heavy clay soil below the raised beds.

Fresh sweet potatoes are extremely fragile, and bruise or break easily. Never throw or drop the tubers – set them down carefully. These garden beds were only a few months old when we took this photo, and we didn’t know what to expect – but it sure wasn’t digging up 120 pounds in this single 50-square-foot bed!

This is a relatively new variety of sweet potatoes, called Covington. We were shocked at the size of the tubers! After all, we don’t live in the deep south, but in the cooler mountains of southwest Virginia, in zone 6B.  But Covington is not a bush-type plant. We had trouble keeping the vines under control, and won’t try growing it again in our small garden.

We also grew a bush variety with shorter vines called Vardaman. It has great flavor, and, if properly cured, stores all winter long in a cool room in our house. These tubers are much thinner, but delicious.

You need to cure sweet potatoes properly before cooking them or storing them. Keep them out of direct sunlight after harvesting them, and cure them with temps in the 80′s and high humidity for 10-14 days. We use our spare small upstairs bathroom to cure our tubers. It has a closet with several built-in shelves that can hold over 200 pounds of sweet potatoes. We have a separate heater in that room, so we set the thermostat around 83 degrees, and run a hot shower for a few minutes a couple of times a day to increase the room’s humidity.

After 10 days or so, you can store them for the winter. We keep our tubers in an unheated closet that usually stays between 55 and 60 degrees. We can eat our sweet potatoes throughout the winter, well into April and May, even after they start sprouting. I always save a few tubers to use to start new slips for our next crop.

Like many other vegetables, you may be amazed at the flavor of your home-grown tubers. One of the big advantages of growing your own vegetables is being able to choose your own varieties, as each variety has its own unique color, flavor, and texture. There are hundreds of varieties of sweet potatoes to choose from. I’m so spoiled now with the incredible flavor of home-grown tubers, that I’m usually disappointed when I have to eat store-bought ones.

Even if you have a small garden, you can enjoy eating great-tasting home-grown sweet potatoes for up to 8 months of the year!