Clock Vine Fast Facts

Clock Vine Fast Facts image by twoblueday/Flickr
Clock Vine Fast Facts image by twoblueday/Flickr


Clock vine, also called sky vine, is a tropical vine from India. Large blue to purple flowers bloom from spring throughout the summer.


The flowers of clock vine are similar to those of morning glory, but larger--as much as 3 inches across. The blooms range from light blue to light purple. Elongated leathery heart-shaped leaves form a lush background for the flowers. Clock vine grows vigorously.


Augusta Blue clock vine has sky blue flowers, while Alba clock vine has pure white flowers. Variegata clock vine has cream and green leaves with blue flowers.


Train clock vine along a fence, on a trellis or over a pergola. Allow it to ramble around and through taller plants. Where the ground freezes, grow clock vine as a houseplant.


Clock vine is hardy in Zones 8 to 11. It is evergreen in frost free areas. The top of the vine will be killed by a freeze, but the plant will return in the spring. Grow clock vine in rich organic soil and keep it moderately moist. Where summers are hot, plant clock vine where it will receive afternoon shade. Prune clock vine regularly to maintain the desired size. Old stems may lose their vigor and need to be removed.


Clock vine is considered an invasive plant in Hawaii and South Florida. Root knot nematode attacks clock vine.


  • University of Florida Extension
  • Center For Invasive and Aquatic Plants

Who Can Help

  • Floridata - Thunbergia grandiflora
Keywords: Clock Vine, Blue Clock Vine, Sky Vine, Thunbergia grandiflora

About this Author

Melody Lee began working as a reporter and copywriter for the "Jasper News" in 2004 and was promoted to editor in 2005. She also edits magazine articles and books. Lee holds a degree in landscape design, is a Florida Master Gardener, and has more than 25 years of gardening experience.

Photo by: twoblueday/Flickr