Thunbergia, Bengal Clock Vine, Blue Sky Vine 'Variegata'

Thunbergia grandiflora

Family: Acanthaceae (ah-kanth-AY-see-ee) (Info)
Genus: Thunbergia (thun-BER-jee-uh) (Info)
Species: grandiflora (gran-dih-FLOR-uh) (Info)
Cultivar: Variegata


Tropicals and Tender Perennials

Vines and Climbers

Foliage Color:


Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Requires consistently moist soil; do not let dry out between waterings

Where to Grow:

Unknown - Tell us


15-20 ft. (4.7-6 m)


15-18 in. (38-45 cm)


USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Sun to Partial Shade


Unknown - Tell us

Bloom Color:

Light Blue


White/Near White

Bloom Time:

Mid Summer

Late Summer/Early Fall





Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

By dividing the rootball

From leaf cuttings

From herbaceous stem cuttings

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:

Glendale, Arizona

Fallbrook, California

Laguna Beach, California

San Jose, California

San Leandro, California

Belleview, Florida

Bokeelia, Florida

Englewood, Florida

Jupiter, Florida

Mulberry, Florida

Niceville, Florida

Ocala, Florida

Ocoee, Florida

Orange Park, Florida

Sarasota, Florida

Seville, Florida

Cordele, Georgia

Baton Rouge, Louisiana (2 reports)

Wilton, New Hampshire

Sumter, South Carolina

Belton, Texas

Humble, Texas

Santa Fe, Texas

Seabrook, Texas

Spring, Texas

show all

Gardeners' Notes:


On Sep 20, 2015, Trilliumfae from Wilton, NH wrote:

This is a great annual here in New Hampshire, but it's also a squirrel buffet. They LOVE the blooms! Doesn't matter what what variety thunbergia. They pop them like potato chips.


On Mar 23, 2014, jtockosz from Belleview, FL wrote:

I started my Bengal Clock Vine from a clipping a friend gave me. I cut it into 3 pieces and all 3 pieces rooted very quickly. The larger piece grew to 3 ft. tall in a few months in a small pot and now I just planted all 3 next to my arbor. The large piece has multiple blooms ready to open. Yesterday, a beautiful large flower opened and another beside it was ready in a day or two. I went out this evening and caught a squirrel eating my flower and the blooms ready to open! Any suggestions on how to stop these critters from eating the blooms? I was so disappointed.


On Dec 9, 2012, ChloeErnie from El Lago, TX wrote:

My purple flowering vine seems to be a Bengal Clock vine, aka Blue Sky vine. - thunbergia grandiflors, however mine has a plain green leaf, not a variegated leaf. The leaves are around 5" long, pointed at the bottom and heart shaped at the top, same shape as in the photos. It 20' tall. Is this a Bengal Clock vine with plain leaves? It is growing in Seabrook, TX.


On Aug 7, 2005, jnc from Sumter, SC wrote:

I bought my Sky Vine at Lowes here in Sumter, S.C. It grew to at least 20 feet the first year , covering a built on trellis across the front porch . It was beautiful ! Cars would stop to look at it . I've not seen another one here . I went back to Lowes to see if they could order another one but they couldn't seem to get any more in . I'm still trying to root some pieces for family members but so far , I've only had one piece to root . Mine died back in the Winter but came back in the Spring . It gets the afternoon sun and only shade in the morning . I think it's a great vine , very showy and easy to grow , as long as you maintain the new shoots that appear every day !


On Jun 16, 2005, Turtle_35206 from Cordele, GA wrote:

I don't grow this, yet...but have watched it on a trellis here for the past five years. It seems to be quite hardy in zone 8A. It is growing in full sun with no shade and seems to bloom from mid June until hard frost.


On Mar 9, 2005, trois from Santa Fe, TX (Zone 9b) wrote:

We purchased this plant about 2 weeks ago. It had several pale blue flowers at the time. It has started growing and the newest blooms are decidedly darker blue that the ones that opened last week. I wonder if they fade to light blue or if the trend will continue.