I love growing underground vegetables with kids. One of my fondest memories is watching my daughter harvest her first carrot. She was amazed that it grew under the soil. Sweet potatoes are another one of the underground vegetable mysteries. The green vines grow strong all summer long, often filling out beds and adjoining rows. Come September, it’s time to harvest. Get your kids to help, and use your sweet potato patch as an opportunity to teach a little about gardening as well.
Ask kids when they think the sweet potatoes will be ready for harvest. Explain that the longer the tubers are in the ground, the bigger their size. Ask what happens to the tubers when the leaves turn yellow or frost comes. Explain that once the leaves start dying, the tubers stop growing and a hard frost can cause the tubers to rot.
Based on your kids’ investigation, start digging your sweet potatoes when the leaves turn yellow but before a frost arrives. They’re easier to dig when the ground is dry and the soil doesn’t clump to the tubers. Have your kids notice where the sweet potatoes are attached to the plants and decide where to dig for the tubers. Most tubers form within 1 foot of the main stem.
Have the kids dig up the sweet potatoes using an iron fork or shovel, being careful not to damage the tubers. Ask kids what might happen to damaged sweet potatoes. These should be the first ones eaten because they will rot fastest in storage.
Let the sweet potatoes sit in the sun for a few hours to let the soil dry. Then clean the tubers and move them into a well-ventilated warm (80 degrees F) room with high humidity for a week or so to cure. Explain that although you can eat sweet potatoes right after harvest, during curing more sugars form, making them tastier. Cook up a freshly harvested sweet potato and compare the flavor with one that has been cured. Once the tubers are cured, move them to a 55 degree F dark basement for storage.