San Marcos Growers LogoSan Marcos Growers
Home Products Purchase Gardens About Us Resources Contact Us
Nursery Closure
Search Utilities
Plant Database
Search Plant Name
Detail Search Avanced Search Go Button
Search by size, origins,
details, cultural needs
Website Search Search Website GO button
Search for any word
Site Map
Retail Locator
Plant Listings

PLANT TYPE
PLANT GEOGRAPHY
PLANT INDEX
ALL PLANT LIST
PLANT IMAGE INDEX
PLANT INTROS
SPECIALTY CROPS
NEW  2026 PLANTS

LIVE AVAILABILITY
  for JULY


Natives at San Marcos Growers
Succulents at San Marcos Growers
 Weather Station

 
Products > Thunbergia grandiflora
 
Thunbergia grandiflora - Blue Sky Flower

Note: This plant is no longer in stock. This is an archive page preserved for informational use.  
Image of Thunbergia grandiflora
[2nd Image]
Habit and Cultural Information
Category: Vine
Family: Acanthaceae (Acanthusą)
Origin: India (Asia)
Evergreen: Yes
Flower Color: Blue
Bloomtime: Spring/Fall
Height: Climbing (Vine)
Width: Spreading
Exposure: Sun or Shade
Irrigation (H2O Info): Medium Water Needs
Winter Hardiness: 15-20° F
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. 

Information displayed on this page about Thunbergia grandiflora is based on our research conducted about this plant in our nursery library as well as from information provided by reliable online resources. We also include our own observations made about it as it has grown in the nursery gardens and other gardens visited, as well how the crops of this plant performed in the containers in our nursery field. We will also include comments received from others and welcome hearing from anyone who has information about this plant, particularly if it includes cultural information aiding others to better grow it.

 
San Marcos Growers closed for regular business at the end of 2025 as the property is being developed for affordable housing.
While our gates remain closed, we will open them by appointment so we can liquidate remaining plants, supplies and equipment. The plants remaining in the field are listed on our Live Inventory Page.
 
  [MORE INFO]