Thunbergia laurifolia, commonly called blue trumpet vine, clock vine, sky vine, or sky flower, is a woody-stemmed, evergreen, tropical, twining climber. It grows to 15-30’ long in frost-free areas. When grown as an annual, it grows to 6-8’ long in a single season. It is native to India. Elliptic to heart-shaped dark green leaves (to 4-8” long) are covered with soft hairs. Trumpet-shaped flowers (to 3”) are lavender-blue with yellow throats. Flowers appear singly or in clusters (racemes) in summer to early fall. Flowers bloom year-round in tropical climates.
Planting & Caring –
Best grown in organically rich, fertile, medium moisture, well-drained soils in full sun to part shade. Appreciates some light afternoon shade in hot summer climates. In St. Louis, it is best grown as an annual vine. New plants may be purchased in spring each year. In the alternative, plants may be grown from seed started indoors 6-8 weeks before last spring frost date. Container plants may be overwintered indoors in a warm sunroom and/or cuttings may be taken in late summer for overwintering.