Common Name: sweet potato vine 
Type: Herbaceous perennial
Family: Convolvulaceae
Zone: 9 to 11
Height: 0.50 to 1.00 feet
Spread: 1.50 to 3.00 feet
Bloom Time: Rarely flowers
Bloom Description: Purple
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Annual, Ground Cover
Leaf: Colorful


Tender perennial that is winter hardy to USDA Zones 9-11. In St. Louis, grow as an annual or dig tubers in fall. Easily grown in average, medium, well-drained soils in full sun. Best leaf color usually occurs in full sun. Consistently moist soils are best. This is a tuberous plant that is not grown from seed. Purchase plants in spring and set out after last frost date. In fall before first frost, dig, dry and store tubers in a dry medium (vermiculite or peat) in a cool dry corner of the basement. When tubers sprout in spring, cut them into sections (at least one eye per section) and plant the sections outdoors after last frost date. Tubers can also be sunk ½ way into a large-mouthed glass jar of water in early spring to generate sprouts that can be removed and planted. Container plants and or rooted cuttings taken in late summer may be overwintered indoors in bright sunny locations. Best to rotate plantings to different locations of the garden from year to year to minimize possible fungal disease problems.

'NCORNSP-021SHJB' is tolerant of some shade, but more sun will produce the deepest purple leaf color and densest, bushiest growth.

Noteworthy Characteristics

Ipomoea batatas, commonly called sweet potato or sweet potato vine, is native to tropical America. It is a tuberous rooted tender perennial that has been cultivated for its orange-fleshed edible tubers for over 2000 years. It was reportedly brought back to Europe from the New World by Columbus. Today, the sweet potato is a popular root vegetable that is grown in vegetable gardens and as a commercial food crop throughout the world. Although species plants and varieties grown as food crops have somewhat attractive green foliage, it is the more recently introduced purple-, chartreuse- and variegated-leaved cultivars that have transformed this vegetable into a popular ornamental foliage plant. If grown as a ground cover, plant stems typically mound to 9” tall but spread by trailing stems to 8-10’ wide, rooting in the ground at the nodes as they go. Leaves of the ornamental varieties are heart-shaped to palmately-lobed (to 6” long) and come in bright green, dark purple, chartreuse and variegated (green with pink or white) colors. Although species plants produce pale pink to violet trumpet-shaped flowers, ornamental varieties usually do not flower. Tubers of the ornamental varieties are edible, but are not as tasty as those of the varieties specifically bred for food production.

Genus name comes from the Greek words ips meaning "worm" and homoios meaning "resembling", in probable reference to the sprawling underground roots of plants in this genus. On the other hand, some experts suggest the genus name is in reference to the worm-like twining plant habit.

The specific epithet batatas comes from the Taíno word for potato, batata. The Taíno were an indigenous group of people from the Caribbean.

'NCORNSP-021SHJB' is an ornamental selection of sweet potato that features dark purple foliage and a compact, mounding to trailing habit. The heart-shaped leaves are held close together on the stems, creating a dense form. Mature plants will reach up to 1' tall and spread to fill a 3' area. Flowers are rarely formed, most often under stressful or reduced day-length conditions. The blooms are purple and funnel-shaped. Commonly sold at nurseries and garden centers under the name SWEET CAROLINE SWEETHEART JET BLACK. Plant patent number PP29378 applies to this cultivar.


Fungal leaf diseases are somewhat common, particularly if plants are grown in the same garden area year after year. Watch for slugs, thrips and flea beetles.


Species cultivars are ornamental, subtropical vines that are most often used as sprawling ground covers or as foliage contrasts grown to hang down over the edge of containers or window boxes.