Scientific Name
Heptacodium miconioides ‘Seven-Son Flower’
Seven-son flower is a plant that often blurs the line between large shrub and small tree. A native of China, it was a bit late to be introduced to the U.S.; this was done by one of the best known and prolific plant explorers, E. H. “Chinese” Wilson in 1907 on behalf of the Arnold Arboretum in Boston. However, it wasn’t until 1980 when more seed arrived from China that the plant became readily available in commerce. Even then it was of conservation concern, and it’s still threatened with habitat loss.
This plant typically grows with a fountain shape up to around 20 feet but can be pruned as it develops to a single stem. There are several at Denver Botanic Gardens that have been managed that way, but the one at Regis thus far has been allowed to assume a shrubbier habit. However, it could still be pruned to encourage a more upright posture. The bark of the plant is thin and exfoliates in strips. The leaves are opposite on the stems and have deeply impressed veins running parallel to the smooth edges.
Seven-son flower is mostly noted for its late-season floral display. The white flowers emerge profusely in September and are swarmed by pollinators. Later, the flowers are followed by small reddish fruits surrounded by showy rose-pink calyces (the modified flower parts) that can last into November.
Mature plants may average around 25 feet in height, which is consistent with the Colorado champions standing at 23 and 26 feet. Seven-son flower is very adaptable to different sun exposures and soil types and is drought tolerant; it can also survive temperatures down to minus 30 degrees Fahrenheit, which we hope it is never subjected to at Regis.