Thunbergia grandiflora Blue Sky Vine, or Bengal Clock vine plant. A beautiful perennial vine that blooms blue to purple trumpet-shaped flowers summer through fall with 6-inch holly shaped leaves. Grows 15 to 20 feet. Great for a fence or trellis, and even containers. Plant in full or partial sun and keep moist throughout the summer. Blossoms from midsummer through the late fall. Hardy in zones 8a to 11. Attractive to bees and butterflies!