If you’re like me, the start of fall is not only exciting for the refreshing cooler weather it brings: It also means I can put up my canning equipment. The wonderful, hearty fall vegetables — winter squashes, potatoes and, of course, sweet potatoes — can store themselves for several months if harvested and stored properly. Sweet potatoes, with the high vitamin content found in their orange flesh, are an especially great and versatile fall and winter food.
After watching the beautiful, winding vines cover your garden beds through the summer months, it can be hard to know when it’s the right time to go grab the spading fork and dig out the fleshy tubers. While sweet potatoes can be dug as soon as the tubers have reached a suitable size — between three and four months after planting the slips — the flavor and quality improves with colder weather. Some even wait until after the first frost has blackened the leaves, but only if you can get all your sweet potatoes out of the ground quickly and right away. Rodale’s Encyclopedia of Organic Gardening makes the following recommendation: “You can harvest as soon as leaves start to yellow, but the longer a crop is left in the ground, the higher the yield and vitamin content. Once frost blackens the vines, however, tubers can quickly rot.”
The most common tool for digging sweet potatoes out of the ground is a spade fork, although a shovel will work, and the ambitious harvester can even adapt a broad fork to dig more plants at one time. If you have a large plot, you can adjust a mold-board plow to mechanically turn the sweet potatoes out of the ground. Tubers can grow a foot or more away from the plant, so give ample space to prevent nicking and damaging the skin, as this encourages spoilage. Digging is much easier when the soil is dry, and mud-coated sweet potatoes are less likely to sun-dry properly and rapidly. For a visual reference, check out this video on how to dig sweet potatoes from The Vegetable Gardener’s website.
Dry freshly dug sweet potatoes in the sun for several hours, then move them to a curing room. Although you can cook sweet potatoes fresh out of the ground, the natural sweetness improves after curing. Proper curing also heals injuries incurred to the tubers during harvest, which helps guarantee successful storage. The simplest curing method is to place the sweet potatoes in newspaper-lined boxes in a warm, well-ventilated room — ideally between 85 and 90 degrees Fahrenheit at around 85 percent humidity — for a week to 10 days. A hoop house or green house works well for this, but any space where you can control the temperature will work. After curing, move the sweet potatoes to a storage space, such as a root cellar, kept between 55 and 60 degrees with humidity of 75 to 80 percent. (If you don’t have a root cellar, you can build your own basement root cellar.)
Now that you have your sweet potatoes dug, cured and stored, look for some great sweet potato recipe ideas on our Relish! blog.
Jennifer Kongs is the Managing Editor at MOTHER EARTH NEWS magazine. When she’s not working at the magazine, she’s likely working in her garden, on the local running trails or in her kitchen instead. You can find Jennifer on Twitter or Google+.
Photo from Flickr/David Bradbeer