Ornamental Sweet Potato Vine new to list of Texas Superstars
by Suzanne LaBrecque/Victoria County Master Gardener and Gardeners’ Dirt editor
August 6, 2021
The ‘Blackie’ Sweet Potato Vine has heart-shaped and lobed foliage and produced trumpet-shaped lavender to pale purple flowers – PHOTO BY SUZANNE LABRECQUE
The ‘Marguerite’ Sweet Potato Vine has a trailing habit of growth, typically spilling over the edges of hanging baskets and containers with good care. PHOTO BY SUZANNE LABRECQUE
Ornamental Sweet Potato Vine – PHOTO BY SUZANNE LABRECQUE
The newest 2021 Texas Superstar is the ornamental sweet potato vine, Ipomoea batatas. Be aware that the ornamental sweet potato vine is somewhat different from the same species that produces spuds. This plant is grown primarily for its tropical-looking foliage and vining habit.
Texas Superstar plants must grow well for gardeners throughout the state. These plants must be easy to propagate, locally available and reasonably priced. Ornamental sweet potato vines meet all the criteria.
Native to tropical America, archaeologists using radio-carbon dating have found prehistoric remnants of sweet potatoes in Polynesia. Columbus is given credit for introducing sweet potatoes to Europe. While popular as a vegetable crop, more recently it has become a popular ornamental foliage plant.
Ornamental sweet potatoes produce vine-like stems similar to philodendrons and ivy. Their drought tolerance and vigorous growth make them excellent choices for hanging baskets, window boxes and container gardens as “spillers” or “fillers.” They are useful outside as mounding ground covers in flower beds or climbing on trellises.
In the Victoria area, sweet potato vines are annuals. They grow 6 to 16 inches tall and have a spread from 3 to 10 feet.
Gardeners can choose from a variety of colors and leaf shapes. The foliage can be shades of chartreuse, gold, bronze, brown, red, purple and almost black. The leaves can be heart-shaped, lacy or deeply lobed.
The most popular sweet potato vines include:
Sweet Carolina “purple,” which has dark purple foliage and small tubers; it is not a vigorous grower so it works well in small containers.
Blackie, which has nearly black foliage with deep cut leaves that are shaped like a bird’s footprint and provide contrast in containers.
Marguerite, which has deep chartreuse green foliage with heart-shaped leaves and often is used as sprawling, mounding ground cover.
Tricolor Pink Frost, which has small variegated, pointy leaves in shades of green, pink and white and does well in containers or window boxes.
Plant after the last frost in the spring and when night temperatures do not go below 55 degrees. They grow best in hot, humid conditions in well-draining and moist, but not soggy, soils.
For rich colors, sweet potato vines do best with at least six hours of full sun daily. They can grow in partial shade but their colors will not be as intense.
In ideal conditions, sweet potato vines can quickly outgrow a space or container. Regular, light pruning or shaping helps them stay bushy rather than growing leggy.
To keep their growth even, apply a water-soluble fertilizer once a month. Do not overwater or let them dry out. Keep the plants moderately moist with weekly watering or more during times of excessive heat.
While tubers on ornamental sweet potato vines are edible, they are typically bitter and meant for propagation, not consumption. In the fall, dig up the tubers, dry and store them in vermiculate in a cool place. In the spring when the tubers sprout, cut them in sections, with at least one sprout per section, and plant them outdoors.
Best practice is to plant tubers in different garden areas each year. Rotating locations will minimize fungal diseases. These healthy plants are resistant to most diseases and pests.
In the winter, sweet potato vines can be brought indoors and treated as houseplants. Also, gardeners can take cuttings before the first frost and place them in water. Once the roots have developed, cuttings can be left in water or potted in containers until spring.
Our neighbor plants the Marguerite sweet potato vine under her magnolia tree. The contrast of the bright chartreuse with a dark green is striking. My sister Michelle has great success combining sweet potato vines with a variety of annuals. Now it is your turn.
The Gardeners’ Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas A&M AgriLife Extension – Victoria County.