By Sharon Reeve, for Let’s Talk Plants! December 2023.
Do you know Bougainvillea 'Torch Glow'?
It is a cool plant! This is unlike any Bougainvillea you have grown previously. The plant happened as a chance mutation of a normal bougainvillea. The plant was patented in 1988. Unlike a normal Bougainvillea, this plant has very congested internodes. See how different it is? 'Torch Glow' has many blooming flowers bunched up on the ends of branches from ten to forty centimeters (4 to 16 inches) down from the tips of the stems. The flowering ends of stems appear to be densely flowering cylindrical spikes or torches. The plant is also very upright growing and more like a shrub than a vine. Typically, bougainvillea have vine-like stems that are 30 feet long. In its native habitat, thorns help it climb to the sun. Bougainvillea 'Torch Glow' stays around six feet tall and four feet wide and looks like a shrub. 'Torch Glow' looks like the normally 30-foot-long stems were compressed into 6 feet with all of the flowers bunched at the tips of the branches.
Isn't this plant amazing? Sometimes when I drive past this plant, I do a double take because at first glance I think it is an azalea. The branches all come from the base of the plant. I have a neighbor who has limbed up B. 'Torch Glow' into a small tree and it looks cool. You can make it look more like a shrub if you trim some of the long wands of leaves. This plant, like regular bougainvilleas, blooms for a long time. The flowers are only the little white bloom in the center, and they are surrounded by colored bracts, like a poinsettia. The bracts are tougher than petals and can stick around for months. It blooms in response to day length in the spring and fall. The plant is pollinated by hummingbirds. Bougainvillea is in the Nyctaginaceae family, along with four-o'clocks (Mirabilis species).
As with all bougainvillea, try not to disturb the roots when planting. For some reason, bougainvillea is especially sensitive to root disturbance and the growth can be set back for quite a while if the roots are disturbed. Bougainvillea has two growth cycles, either vegetative or blooming. After it finishes blooming, it grows stems and leaves. If there is plenty of light, and things aren’t too cushy, the plant will also form floral buds. Once the vegetative cycle is completed the plant will flower again, typically, in the spring and fall, when the daylight and night lengths are approximately the same. Besides high sunlight and heat levels, the plant responds to stress and will bloom again, if you skimp on water and avoid high nitrogen fertilizer.
The more sunlight and heat you can provide-- the better. This plant thrives on neglect. If you treat it too nicely, it will fail to rebloom and continue to grow only stems and leaves. Let your plant dry out, quite a bit, before watering again. Observe, and allow the leaves to almost wilt before watering again. Make sure the soil drains well. This plant grows best in sandy low-fertility soil. This plant will not tolerate heavy clay or badly draining soil. If you treat it too well, with abundant water and fertilizer, it will only grow leaves. Prune right after blooming. This plant is hardy to Zone 10 and will not tolerate freezes. It thrives on heat. This is not a problem where I live, but you may need to place it in a south-facing position, and siting it next to a cement sidewalk or masonry wall will increase the heat if necessary. You can, and people certainly do, overwinter bougainvillea all over the country if they are in a less-than-10 zone. I love this plant! Isn't it cool?
Sharon Reeve is a Master Gardener who has worked as a consulting Horticulturist for Monrovia Nurseries, and as a landscape designer for BrightView Landscapes in San Diego. In 2015, she graduated with an MS from SDSU in Biology/Ecology. Her design business is called ReWild. She specializes in drought tolerant, native, and wildlife gardens, and writes two blogs.
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