The ornamental sweet potato vine sprouts tubers, but they are considered inedible.
Surprisingly, the ornamental sweet potato vine is not related to the potato, but the morning glory. Gardeners value this leafy plant for its beautiful foliage, not its bitter-tasting tubers. Ipomoea batatas are winter hardy in the warmer climes of the southern United States, but grow as annuals elsewhere. The spilling, fast-growing vines make for an impressive container plant or ground cover. For purple foliage, gardeners turn to the Blackie or Sweet Caroline varieties.
Blackie
The Blackie variety features deep purple to burgundy-black leaves that are large, heart-shaped and lobed. Grown as an annual in all but nearly tropical environments, the Blackie makes an excellent specimen in beds, borders and containers. Grown in full sun in moderately fertile, well-drained soil, the Blackie sports trumpet-shaped, pale purple flowers in the summer and fall -- but, like all ornamental sweet potatoes, it is grown for its foliage, not its blooms.
Sweet Caroline Purple
The Sweet Caroline ornamental sweet potato was developed in 2002 by researchers at North Carolina State University. The Sweet Caroline Purple is grown as an annual, except in USDA hardiness zones 10 and 11. With its dark purple to almost black foliage and its propensity to spill and spread, it makes a great ground cover or container plant. When grown as an annual, the tubers can be dug out and stored over the winter in a dry space in the basement. After the tubers sprout in the spring, they may be cut and planted in the outdoor garden after the last frost.
Sweet Caroline Sweetheart Purple
Like the Sweet Caroline Purple, the Sweetheart variety makes an excellent annual ground cover or hanging plant with its purple to black leaves and its spilling, fast-spreading vines. Prized for its heart-shaped purple leaves, the plant produces the best foliage color in full sun. When grown as an annual, the tubers may be dug up before the first fall frost, stored over the winter and planted in the outdoor garden after the last spring frost.
Sweet Caroline Bewitched Purple
The Sweet Caroline Bewitched Purple stands alone among ornamental sweet potatoes with its one-of-a-kind, maple-leaf-shaped, purple to almost black leaves. Like all Sweet Caroline varieties, the Bewitched is less aggressive in the garden than other ornamental sweet potatoes and a more compact garden plant. Planted beside the bright, lime-green of the Sweet Caroline Sweetheart or the lemon-lime leaves of the Marguerite, the Bewitched makes a striking statement in the garden landscape.
Tags: Sweet Caroline, ornamental sweet, Caroline Purple, ground cover, grown annual, ornamental sweet potato
