What is a blue sky vine?

The blue sky vine, Thunbergia grandiflora, is a quick-growing vine native to northern India. In the United States, it is a winter-hardy perennial with aggressive growth in zones 10 and 11. In zones 8 and 9, the blue sky vine can be grown as an annual.

The vine produces 2- to 3-inch light-blue or lavender-blue, trumpet-shaped flowers in the summer, which attract butterflies. The leaves are heart-shaped, with a leathery texture and a dark-green color. The blue sky vine can be grown in containers or baskets in areas where it grows as an annual. In the frost-free zones, where it grows as a perennial, it can be planted to cover a trellis or an arbor, and the leaves stay green all year.