At a glance
Latin Name: Thunbergia
battiscombei
Common Name: blue glory vine, blue clock vine, blue boy
Family: Acanthaceae (Acanthus)
Origin: Tropical Africa
Plant Type: herbaceous perennial scrambler
Flowers: 2-inch, pure blue trumpets with a yellow throat
Foliage: Bright green simple leaves
Mature height: 4-6 feet
Hardiness: Zones 7-11
Soil: Well-drained
Exposure: Full sun to afternoon shade
Water usage: Medium
Sources: Mail-order or local nurseries
About 15 years ago, I was working at a wholesale nursery in
Dallas, and while I was loading plants into the back of a customer's station
wagon I spied a plant I'd never seen before. This particular customer had a
knack for finding neat and new plants, so he eagerly dug it out from behind
the carload of plants to show me his latest find. Dangling before my eyes
was a hanging basket filled to overflowing with lush, tropical foliage
punctuated with the most incredible blue flowers. I think he saw the lust in
my eyes, or maybe it was the fact that I bluntly mentioned that he had two
of the beauties - either way, he gifted me with that plant.
Needless
to say, I immediately hit the references searching for its name. Since it
was in a hanging basket, I assumed it was a tropical groundcover or vine. I
discovered the plant in question was Thunbergia battiscombei, or blue clock
vine, related to black-eyed susan vine (T. alata) and blue sky vine (T.
grandiflora), both of which are annuals in my Zone 7 to 8 garden.
T. battiscombei has incredible, deep-blue flowers, without any of those
violet or purple tones that are so commonly called blue. In the middle of
the 2-inch-wide flowers is a small yellow throat that makes the blue "pop"
even more. Foliage is a deep, glossy green and makes the perfect backdrop
for the flowers.
One thing I quickly discovered is this plant really isn't a true vine or
shrub - I'd call it more of a leaner. The stems tend to lay around and on
top of whatever is nearby; they will not climb on their own. Now that I've
become more acquainted with this plant I actually like this growth habit. It
is perfect for growing on those wrought iron trellises in containers or
winding through chain link fence. So what it needs a little extra help?
Also, it's just the right size - not too large or too small. The stems
will grow
about 6 feet long at the most, so it stays just constrained enough that the
flowers are level with your eyes, unlike many other vines that want to
flower on top of your house or somewhere over in your neighbor's yard.
Blue glory vine loves it warm - the hotter it is the more flowers it
makes. I've found that it will grow in full sun to afternoon shade. Just
remember, the more sun it is in, the more you'll have to water it. It isn't
too picky about soil, but the richer the growing medium, the bigger the
plant and the more flowers you'll get. I've found it grows equally well in a
container or in the ground. In fact, that first plant I received stayed in a
20-inch-square plastic pot on my back patio for nearly 9 years. Yes, I said
9 years! I didn't have room to bring it in the first winter, and I never
thought in a million years it would actually come back up the next spring.
But, it did. For years.
Blue glory vine may be a little hard to find. Sorry, I can't help that.
Unfortunately, local nurseries and growers don't consult me about what
plants to buy and it just isn't worth writing about plants you kind find
EVERYWHERE. Gardening should be an adventure, not a process. So, break out
your computer do some searching on Google, or visit your local nursery and
beg them to hunt for it. I've seen wholesale growers listing it this year,
so I know it's available.
Oh, and by the way John M. if you're reading this, thank you for that
great plant and all the others you gave me over the years!
About the author: Jimmy Turner is the Director of Horticulture Research
at the Dallas Arboretum, visit www.dallasplanttrials.org for more
information on his trials.