PlantFiles: King's Mantle
Thunbergia erecta

I've had this plant growing in semi-shade under a redwood tree (sequoia) for years. It seems deciduous (not evergreen) and dies back in Feb or March. I trim the dead stalks, and the new green comes back happily. It has spread some since I planted the original (from a 1-gallon container) and now roots in an area 2- to 3-feet in diameter. It's not invasive, however, just increasing its foothold slowly after about 20 years. The bush itself spreads 4 to 5 feet, and it's almost 3 feet tall. It blooms with intense blue flowers most of the summer. I water with a drip line. Occasional sprinkler, too.

The nursery I work for received a couple of these plants along with other assorted tropical climbers a few years ago. I'd never seen the plant before and conveniently there were a couple broken branches which I brought home a rooted in water. They seem to root very easily and quickly, and were potted up within a couple weeks. They began blooming the second summer, and although I can't say that the plant has ever bloomed heavily (there are usually just a couple flowers at a time) it does bloom reliably from mid summer through late fall. The flowers are always a surprise since it seems that the buds remain hidden in the foliage until the blooms pop out, and it seems that most of the bud set occurs near the base of the plant. The plant is now in a 12" pot, is about 40" high and for me grows as a sort of thin stemmed shrub with no inclination to climb at all.
It seems to remain pest free, even though I have been battling a pretty serious mealy bug and mite infestation on some other plants for the past year or so. The only down side to the plant is this: it grows profuse leafy growth from spring through mid-summer. At about the time of the first flowering many of the leaves develop yellow/brown tips and edges and fall off. I'm not sure if this is a natural thing or if I just haven't found the correct fertilizing/watering/lighting requirements for this plant. In any event the flowers are striking and the plant itself seems very tough, even if it does look a bit ratty at flowering time.

I planted three of these beautiful plants to go over a trellis about a month ago. Some of the tendrils have already reached six feet. They are all healthy and insect free. I am anxious to see if they seed or not as I am trying to root some now.

This plant is one of my favorites in my garden. It is not always easy to come by in the nursery. In southern California it dies back completely into the ground in the fall and re-emerges in spring. The flowers are absolutely wonderful and it seems to bloom from early spring until late summer or fall. I
have them in partial shade/sun. I hope more people will give this lovely plant a try.

Thunbergia erecta is one of my favorite flowers in my garden. I use it at the back of the border in many of my beds.I love the royal purple flower with the yellow throat. It can be grown as a bush with weeping branches or it can be trained like a vine. It sometimes produces seeds which will make volunteer seedlings; but that doesn't happen often. Here in Hawaii it blooms year round.