Can the sweet potato plant be grown indoors as a houseplant?
Many sweet potatoes that you find in the supermarket have been kiln dried or treated with chemicals to keep them from sprouting. This may cause a problem if you try to grow plants from store-bought roots. Go to a farmer's market or organic vegetable store and select your sweet potato there. Preferably, choose one that shows signs of life such as roots or buds.
About one-third down from the top of the sweet potato, insert toothpicks into the side of the sweet potato. The top is the rounder-shaped end. The roots will emerge from the tapering end. Set the potato in a tall glass or jar of water. Keep adding water to replenish what evaporates. Change the water if it becomes cloudy. With a little luck, you will have your sweet potato vine.
There are a number of ornamental sweet potato cultivars now available. Several, including "Blackie" and "Margarita", have been used as outdoor groundcovers in the South. They will do very well as houseplants, and they will eventually produce tuberous roots similar to other sweet potato varieties.