The climbing shell plant (Vigna caracalla), also known as the corkscrew flower vine or caracalla bean, is a tropical vine that's native to South America. Growing rapidly to 25 feet tall and 3 feet wide, the climbing shell vine blooms in clusters of curled, shell-like white and lavender flowers. The snail shell-shaped flowers are heavily fragrant. The climbing shell plant grows best outdoors in USDA Hardiness Zones 9 through 10, where summers are hot and winter temperatures stay above 30 degrees F. This plant can also be container-grown and kept indoors in colder climates.
Water your climbing shell plant deeply to soak the roots once each week throughout the spring, summer and fall. Ensure that the vine receives at least 1 inch of water per week if you're growing it in the ground outdoors, or water the vine two to three times per week if you're growing it in a container.
Plant your climbing shell vine in a location that receives full sunlight. If you're container-growing the vine, set the plant outdoors in full sun during the warmer spring, summer and early autumn months or place the vine in a sunny, south-facing window.
Prune back the vine stems of your climbing shell plant each year in the spring to keep the plant tidy and growing healthy. Always prune the stems back to a healthy set of flower buds.
Provide a climbing support, such as an arbor, fence or trellis for your climbing shell plant. You can also allow the plant to trail along the ground if you have the space.