Harlequin Glory-Bower, Clerodendrum trichotomum, is a member of the genus Clerodendrum which is a genus of many species scattered primarily throughout the tropical areas of the world. There are two relatively hardy species that were also known, though not native, in Europe (probably C. trichotomum and C. bungei). The name Clerodendrum originates from the Greek, kleros, meaning chance or destiny and, dendron, meaning tree. The name comes from an old tradition that one of the two hardy species known in pre-Linnaean Europe was believed to be "the tree of good fortune" and the other was believed to be "the tree of bad fortune". Unfortunately for modern gardeners we don't know which was which!
C. trichotomum, the Harlequin Glory-Bower, is a native of China and Japan. It is a loose, open, somewhat unkempt looking multi-stemmed shrub that will eventually reach about 5 to 10 feet and spreads to the same width. It can be trained to a tree form by judicious pruning and diligent removal of suckers. Large, dark green, relatively coarse foliage is scattered along slightly fuzzy branches to the ground. The overall shape is rounded but the open habit makes the shape a bit irregular.
The reasons to grow Clerodendrum are its lovely flowers and brightly colored fruit. It begins blooming in mid-summer when few other flowering shrubs offer color and will continue flowering until first frost. The flowers are a beautiful soft white with a prominent, red calyx (a group of outer, petal-like structures fused at the base of each flower). The strongly fragrant flowers are long and tubular, opening into 5 relaxed petals surrounding exceptionally long stamens (the delicate, thread-like 'hairs' growing from the flowers' centers which carry the pollen-bearing anthers at their tips). The flowers have an airy, sweetly delicate grace and are large enough to make an eye-catching show. The fruits of Harlequin Glory-Bower are equally interesting, although they require a closer look to fully appreciate them. The red calyx persists as the fruit develop into small bright blue berries making a very colorful combination. The leaves quietly drop in the autumn with no show of fall color and may still be green when they fall.
Harlequin Glory-Bower is hardy throughout the southeast, except in the mountainous areas where temperatures drop into the teens and there it can be grown as an herbaceous perennial. It prefers moist, well-drained soils but has grown well in the Piedmont clay soils at The NCSU Arboretum (now the JC Raulston Arboretum). Shape and flowering are best in full sun but the plant will grow and flower also in partial shade, although the already loose habit will be even more open there. Propagation is easy from seed or cuttings taken from partially hardened wood in early summer and rooted under mist.
There is a botanical variety of C. trichotomum, var. fargesii, native to China and Taiwan, that is similar to the species but has smooth stems and lacks the red color in the calyx. This botanical variety has such strong fragrance that it can be offensive to sensitive noses!
Clerodendrum bungei, the French Hydrangea or Red Mexican Hydrangea, is taller and more upright than C. trichotomum with large, heart-shaped foliage and rounded clusters of purple-pink flowers similar to those of C. trichotomum except that the individual flowers are smaller and are borne in large heads. C. bungei is not as hardy as C. trichotomum which is the preferred species for the southeast.
Harlequin Glory-Bower is a wonderful informal flowering shrub for a mixed border or grouped planting of several shrubs behind other planting beds. Because the foliage is not especially dramatic, it blends well with other plants but adds its own beautiful flowers and fruit to any planting at a time of year when few woody plants are offer such a striking show. At The NCSU Arboretum (now the JC Raulston Arboretum), Clerodendrum trichotomum is tucked beyond the large Tilias on the eastern border of the Arboretum where it brings graceful and unpretentious beauty to the garden. Come out to the Arboretum to see the delightful mid-summer bloom of Harlequin Glory-Bower. br>