Ornamental sweet potato vines are a classic "spiller" plant perfect for container gardening. They are cultivars of the same species as edible sweet potatoes but are only ornamental, not edible, as they are very bitter. This beautiful, fast-growing tender herbaceous perennial is native to tropical regions of the Americas and best planted in the spring once temperatures consistently stay about 50 degrees Fahrenheit. It has long tendrils that tumble over the edges and down the sides of containers. Sweet potato vines are available in various colors—from almost black to chartreuse—and with several different leaf shapes.