When the average North American thinks of sweet potatoes, (Ipomoea batatas) large orange tubers used in cooking likely comes to mind. However, the vines and colorful leaves of this nutritious plant are also edible -- raw or cooked -- and have contributed to salads, soups and stir-fries for hundreds of years in many other parts of the world. When you add the beauty of the vine to the vigor of its growth habit, and its effectiveness as a ground-cover and ornamental hanging plant, the sweet potato is exceptionally useful, whichever color you choose to grow.
The Sweet Potato
The sweet potato we know today derived from a wild cultivar -- probably Ipomoea trifida -- and is a native to Central and South America. The leaves of the original sweet potato are heart-shaped and medium green, but careful selection and hybridization now give us many variations on that basic leaf shape and color from which to choose. Sweet potatoes are perennials, generally hardy to United States plant hardiness zone 9 and are frost-tender.
Purples and Blacks
Horticulturalist Dr. Gary Bachman of Mississippi State University, recommends the Sweet Caroline series, with their choice of cut-leaf or heart-shaped leaves and multiple colors, for landscape plantings, as well as the dark purples and burgundies of “Garnet Lace” and “Midnight Illusion.” “Sidekick Black Heart” is another pretty variety with heart-shaped, purple-green leaves.
Greens and Yellow-greens
All ordinary sweet potatoes planted in soil produce leaves, and those grown for their roots and sold in supermarkets are generally dark green, but the green ornamental cultivars range from deep emerald to the palest of yellows -- with all shades in-between. One particularly stunning new green variety is “Sweet Caroline Light Green,” a cut-leaf variety in bright chartreuse with pencil-thin burgundy outlines on the leaf margins. Despite its name, “Illusions Emerald Lace” is a lime-green, thread-leaf variety. “Margarita” is another bright yellow-green variety with narrow, heart-shaped leaves resembling arrowheads.
The red group of sweet potato vines vary from the almost-pink over green leaves of “Bright Ideas Rusty Red” to the deep wine of “Sweet Caroline Red Leaf.” The red group provides nice color variety, with leaves ranging from a sort of gray-green with red tints, through dusty reds, brick-red and bronze to almost black. Sweet potatoes do not care for shade, and full sun greatly enhances the darker colors.
“Tri-color” sweet potato vine is a smaller, more compact variety with narrow, palmate, cut-leaves closely resembling maple leaves. The mostly mint-green leaves are splashed with palest pink and white along edges and veins for a pretty marbled effect. “Pink Frost” is another lovely variegated sweet potato vine with somewhat more pink in the mix.