Thunbergia Species, Blue Boy, Blue Glory, Clock Vine

Thunbergia battiscombei

Family: Acanthaceae (ah-kanth-AY-see-ee) (Info)
Genus: Thunbergia (thun-BER-jee-uh) (Info)
Species: battiscombei (bat-tis-COM-ee-eye) (Info)
View this plant in a garden



Tropicals and Tender Perennials

Vines and Climbers

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun

Sun to Partial Shade




Foliage Color:

Unknown - Tell us


24-36 in. (60-90 cm)

4-6 ft. (1.2-1.8 m)


4-6 ft. (1.2-1.8 m)


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)

Where to Grow:

Grow outdoors year-round in hardiness zone

Can be grown as an annual


Unknown - Tell us

Bloom Color:

Dark Blue

Medium Blue


Medium Purple

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Late Fall/Early Winter

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:


Propagation Methods:

From softwood cuttings

From seed; sow indoors before last frost

By simple layering

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant is said to grow outdoors in the following regions:

Daphne, Alabama

Mobile, Alabama(2 reports)

Spanish Fort, Alabama

Cloverdale, California

Elk Grove, California

San Francisco, California

Stockton, California

Brooksville, Florida(2 reports)

Clermont, Florida

Crawfordville, Florida

Daytona Beach, Florida

Deland, Florida

Gainesville, Florida

Haines City, Florida

Hollywood, Florida

Jacksonville, Florida

Keystone Heights, Florida

Lady Lake, Florida

Melbourne, Florida

New Port Richey, Florida

Port Saint Joe, Florida

Saint Augustine, Florida

Sarasota, Florida

Venice, Florida

Winter Springs, Florida

Macon, Georgia

Richmond Hill, Georgia

Thomasville, Georgia

Pukalani, Hawaii

Latonia, Kentucky

Covington, Louisiana

Greenwell Springs, Louisiana

Lafayette, Louisiana

Ocean Springs, Mississippi

Bridgeton, Missouri

Denville, New Jersey

Averill Park, New York

Bartlesville, Oklahoma

Salem, Oregon

Myrtle Beach, South Carolina

Okatie, South Carolina

Cookeville, Tennessee

Alvin, Texas

Arlington, Texas

Austin, Texas(2 reports)

Conroe, Texas

Cypress, Texas

Galveston, Texas

Houston, Texas(2 reports)

New Caney, Texas

Refugio, Texas

Spring, Texas

Stephenville, Texas

Lynchburg, Virginia

Newport News, Virginia

show all

Gardeners' Notes:


On Aug 28, 2016, coriaceous from ROSLINDALE, MA wrote:

In frost-free climates, this tropical perennial blooms year-round.

This species is often called a climber, but it has neither tendrils, nor holdfasts, nor the capacity to twine. It's a sprawler, leaning over its neighbors and flopping. It continually puts out new flowering stems, so if you're trying to tie it to a trellis, you have to do so frequently. Or you can put in a web of what the British call pea-brush for support. It's the perfect scale for a traditional garden obelisk.

The stems can self-layer where they touch the ground.

But it's well-behaved, as few tropical vines are.


On Jun 9, 2015, gtbabic from The Villages, FL wrote:

In zone 9A, appears to survive over-wintering fine and comes back very strong. Loads of unusual purple flowers with yellow "throats" on an extended flower from early spring thru frost. Mine is on a small trellis, would do better on a larger trellis or fence where it could be spread out to showcase the flowers. Overall very attractive.


On Oct 24, 2014, pjbanshee from Refugio, TX wrote:

My flowers don't open before they fall off, what is happening?


On Oct 17, 2011, cathy4 from St. Louis County, MO (Zone 5a) wrote:

I received 3 starts in early spring. It grew like crazy once it warmed up here. I have it in a big pot and will overwinter it in a cool but sunny greenhouse, hopefully it will survive because the flowers really are blue, my favorite! If it makes it through the winter, I will be sharing next spring (2012)
BTW, the seeds are tiny, put a little silky bag over the developing pod if you want to collect them. When the small pod is ready, it explodes and the seeds fly all over. Very hard to collect if you don't have them bagged in advance.


On Jan 11, 2011, sunkissed from Winter Springs, FL (Zone 9b) wrote:

I just love this plant, it is the cousin to the blue sky vine (Bengal clock vine), looks quite a bit like morning glory, but stays pretty much in its place. It will freeze to ground when temperatures get below freezing, but comes back fuller every spring. It is one of the first things to bloom in my garden each spring, and blooms all the way until first freeze. I do have to tie it to a trellis or it will grow on the ground once branches are long enough to fall due to weight. Hummers and bees love to visit the blooms. Mine gets full morning sun and filtered sun to shade from noon until sunset. Does fine with twice a week irrigation, heavy rains don't seem to affect it either.


On Aug 12, 2010, bobyrd from Conroe, TX (Zone 9a) wrote:

Once this plant gets started it really takes off and blooms non stop. In my area the flowers close up in the heat of the late afternoon. I have yet to figure out where the seeds are if there are any! I have this planted where it gets afternoon sun but am eager to see how it does in partial shade.


On Jun 28, 2008, 9kittymom from Bartlesville, OK (Zone 6a) wrote:

I love this vine. I bought it last year from Logee's and it bloomed a little bit. I wintered it over in my garage because it wouldn't make it in my zone. It has come back and is lush and loaded with buds and blooms. Just Gorgeous!


On Jul 8, 2007, largosmom from Newport News, VA (Zone 7b) wrote:

This plant was recommended to me as an annual in my area for a quick covering vine for a section of chainlink that is visible between the neighbor's house and mine. I'm very pleased with the bright blue blossoms and wish I'd put it on a terrace (next year!). I plant to collect cuttings and/or seed in the fall so that I can grow my own. In profile, the yellow throat shows, and it resembles a smoker's pipe.


On Jun 25, 2007, princessnonie from New Caney, TX (Zone 8b) wrote:

In my zone which is 8b/9a this plant wilts in late afternoon summer sun but recovers.
It freezes to the ground in winter but comes back from the root in time to reach 3 to 4 feet tall and blooms well.


On Aug 31, 2006, mia01 from karachi,
Pakistan wrote:

mia01 31 Aug 06 Karachi

This plant is a joy to behold! I have had it in my garden for over a year now. From a small cutting it has grown into a most pleasing 4 foot high bush and flowers faithfully. My only regret is that the gorgeous deep purple flowers are very shortlived.

I am quite certain mine is the thunbergia battiscombei but, unlike lilypons, it is quite unmistakably small-leaved. I will post a picture of it ....if I can only figure out how...


On Oct 6, 2004, Lilypon from Moose Jaw, SK (Zone 3b) wrote:

This one is a winner (for spending the winter in a zone 3 grower's window). I really am following in love with:
Common name: Blue Boy or Clock Vine
Family: acanthaceae
Genus: thunbergia
Species battiscombei

It started blooming outside and even tho it dropped it's buds with constant hauling in and out (spending three days in a dark shed, avoiding frost, didn't help) it has now come back strong and is covered with buds/flowers. I really think it is a winner for growers in lower zones. Should also mention it blooms the first year from a small cutting. Just be aware it is a larger leafed vine and has a huge root systerm (needs a very large pot).


On Jan 30, 2003, lupinelover from Grove City, OH (Zone 6a) wrote:

Great for weaving among other plants.