If you planted sweet potatoes this year it’s about time to get them out of the ground, if you haven’t already. That said, most of mine are still there, I hope. The only pest I have with sweet potatoes are the voles and they may have gotten more than their share this year. Voles are one of the biggest challenges in the garden. One of these days I’ll have them in balance.
According to the Rodale book How to Grow Vegetables and Fruits by the Organic Method (1961), my favorite reference book, sweet potatoes need 175 frost-free days with warm nights. When the soil temperature dips to 60 degrees the vines stop growing. The vines die at a soil temperature of 50. I want to dig my sweet potatoes before the frost so that I can have as much biomass for the compost pile from the vines as I can. If you do that you don’t have to worry about soil temperature. Sweet potatoes grow as a bunch from the base of each plant, not willy nilly under the ground. You can see the harvest from one plant in the photo along with the garden fork used to dig them. Garden forks have strong, flat tines as opposed to pitch forks which have round tines for forking hay and such. Pitch forks are not suitable for digging in the soil. You can see me digging sweet potatoes in my video Cover Crops and Compost Crops IN Your Garden.
Once the sweet potatoes are out of the ground the books generally say to cure them at about 80 degrees for a week or two. They sweeten up during that time so you may want to hold off eating them. Unless the house is 80 degrees, which it’s not in early October, my sweet potatoes don’t get the heat treatment. I bring them in, usually unwashed, and store them in the sunroom in a bushel basket or cardboard box, maybe covered with a newspaper, for at least two weeks before further handling. We often just use them out of that basket. Late in October I’ll sort them and put the ones I want to save for starts next year in a plastic 10-gallon tote with a lid, first making sure they are dry enough. That plastic box has air holes drilled in it and goes into the crawl space under the house. If I have extra Irish potatoes, they are stored the same way. When I retrieve any potatoes from a bin in the crawl space I peek at all the boxes to make sure none are rotting. You could store sweet potatoes under your bed in a cardboard box. Irish potatoes, however, need a little cooler temperature and higher humidity, so under the house in the ventilated plastic tote is best for them. I store a good quantity of sweet and Irish potatoes in a lower kitchen cabinet for immediate use. We don’t have a dishwasher, leaving plenty of space for things like that.
You can actually begin your harvest from the sweet potato plants much earlier by harvesting the leaves for your table. We began cutting the tips of the plants this summer to add to a stir-fry vegetable medley. I would go into the garden and get a little of this, a little of that, and some sweet potato leaves, add some onions and/or garlic and toss it all around in a pan with a little olive oil or bacon grease. I would take the newest leaves on the end of each vine. As you can see in the photo, they are brighter and slightly red veined. I plan on doing more of that in the future. Of course, you don’t harvest too much. You would have to experiment to determine how much you can cut. If small livestock are part of your food production circle you could harvest the green vines for them. You’ll get the benefit back when the manure goes into the compost. Sweet potatoes were part of the diet in the Biosphere II experiment, with the vines going to their goats. I have heard that cutting the vines during the growing season would result in bigger potatoes, but I haven’t thoroughly explored that yet.
Sweet potatoes have the highest beta-carotene content of all the vegetables, even carrots. Studies indicate that beta-carotene can help protect you from cancer, particularly cancer of the lungs, stomach, or mouth, which should be of particular interest to smokers. In order for your body to make the best use of beta-carotene, add a little fat to your sweet potato dish. A pat of butter will do. Sweet potatoes are healthy for you, taste great, and are easy to store. All good reasons for you to have them in your garden plan.