Culture
Winter hardy to USDA Zones 10-12 where it is 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. Flowering decreases in too much shade. Plants appreciate consistent moisture throughout the growing season. Plants die to the ground in winter in USDA Zones 8 and 9, but usually will come back in spring. In St. Louis, it is best grown as an annual. 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 sun room and/or cuttings may be taken in late summer for overwintering.
Noteworthy Characteristics
Thunbergia is a genus of about 100 species of annuals, perennials, shrubs and vines from tropical Asia to tropical and southern Africa and Madagascar. They are grown for their showy flowers.
Genus name honors Carl Peter Thunberg (1743-1828), Swedish botanist. He traveled in South Africa and Japan and became professor of botany at Uppsala University.
'Blue Glory' is a weak-stemmed vine that grows to 2-3' tall. It does not climb, but typically scrambles over and through nearby perennials and shrubs. Heart-shaped, dark green leaves (to 4” long). Five-lobed, trumpet shaped flowers (to 2” wide) are royal blue with yellow throats. Flowers appear singly or in clusters (racemes) from June to early fall. Flowers bloom year round in tropical climates. 'Blue Glory' is sometimes sold in commerce as a cultivar of Thunbergia battiscombei.
Problems
No serious insect or disease problems. Watch for scale, spider mites and whiteflies.
Uses
Trellises, arbors, fences or other structures in areas where winter hardy. Hanging baskets and other containers when grown as an annual. Houseplant.