Climbing shell plant, also known as snail vine or corkscrew flower, is a perennial climbing vine valued for its ornamental flowers and ease of care. The vine's flowers form a spiral pattern, similar to that of a sea shell, hence the common name. Climbing shell plant blooms during mid-summer to early fall, producing numerous white flowers saturated with hues of pink and yellow. Native to Central and South America, climbing shell plant thrives outdoors in USDA hardiness zones 9 and 10 only, though with proper care it often is grown in colder regions.
Plant climbing shell plant during mid-spring, just after the final frost of winter. Choose a planting site that consists of well-drained, rich, moist soil and receives full sunlight throughout the day.
Dig a hole in the soil of equal depth and twice as wide as the plant's root ball. Insert the roots into the hole and gently back-fill with soil. Water lightly to compact the soil and collapse any air pockets. Space climbing shell plants at least 5 to 6 feet apart.
Place a support structure at the planting site for the vine to climb, such as a wall, fence, stone, wire or trellis. Loosely secure the plant to the structure with garden twice until it is able to support itself.
Water the climbing shell plant once every five to seven days to keep the soil consistently moist but not soggy. Decrease watering frequency to once every 10 days during winter, when the plant is not actively growing and requires less water.
Feed once per month during spring, summer and fall to keep the plant growing fast and healthy. Apply a balanced 10-10-10 NPK granular fertilizer, using the rate recommended by the manufacturer. Water before and after fertilizing.
Prune climbing shell plant any time of year to keep the vine aesthetically pleasing and growing in a compact habit, if desired. Cut back any vines that are excessively long, damaged or bare.