Thunbergia grandiflora (Blue Sky Flower) - A vigorous evergreen vine with thick tuberous roots from which emerge rope-like stems holding 4-5 inches long dark green leaves that have a slightly toothed margin. From mid-summer to late fall appear the beautiful 3-inch wide, pale blue , tubular flaring flowers that are cup-like with pale yellow to cream blue striped centers.
Plant in full sun or in a shaded location - does not bloom well in shade but this vine will climb high to find the sun! Tuberous roots give this tropical looking plant considerable tolerance to summer dry conditions so can be watered regularly to only infrequently in coastal gardens. It is hardy and evergreen to 25° F and if frozen to the ground (as it was here in our very cold December 1990 at 18° F) it can resprout and grow into a large vine within one season - some claim it root hardy, likely with mulching, to 10°F. A very attractive vine that can cover fences and climb high and wide onto supporting structures or trees.
Blue Sky Flower naturally ranges from China (Fujian, Guangdong, Guangxi, Hainan, Yunnan) India, Myanmar, Thailand and Vietnam but has also naturalized in tropical regions worldwide. The name for the genus honors the Swedish naturalist Carl Peter Thunberg (1743-1828), who was a student of Linnaeus and spent several years botanizing the Cape of Good Hope. The specific epithet is from the Latin words 'grandis' meaning "great" or "large" and 'flora' meaning "flower" in reference to the flowers which are large for the genus. Another common name for this plant is Bengal Clock Vine. This plant received the prestigious Royal Horticultural Society's Award of Garden Merit in 1993. It was first introduced into cultivation in California by the Italian botanist Dr. Francesco Fenzi (AKA Emanuele Orazio Fenzi) at this Santa Barbara Southern California Acclimatizing Association nursery in 1906. We have grown this large attractive vines since first listing it in our 1984 catalog.
The information about Thunbergia grandiflora displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant. |