Seven-son flower: an autumn-flowering delight
As summer draws to a close and the days grow shorter, September brings a plethora of flower color to the garden.
Herbaceous perennials like aster, chrysanthemum, sedum, goldenrod, Japanese anemone, and many ornamental grasses dominate the garden and provide the most flowering. After late summer in New England, only a handful of woody plants continue to bloom, including roses, hibiscus, hydrangea and sumac that are finishing their bloom periods.
Among the very few winter-hardy trees and shrubs that start their bloom after August are the native witch-hazel (Hamamelis virginiana), the Franklin tree (Franklinia alatamaha) and sweet autumn clematis (Clematis paniculata). None of these, however, have proved as reliable and spectacular as the seven-son flower (Heptacodium miconioides). Because it is so underutilized in the landscape and exhibits such attractive features every season of the year, it was recognized in 2002 as a Cary Award winner (go to www.CaryAward.com).
Originally brought to the United States as a herbarium specimen in the early 1900s by Ernest Wilson at the Arnold Arboretum, Heptacodium remained obscure until 1980, when a Sino-American Botanical Expedition provided seeds and the opportunity to introduce living plants to North America.
A member of the honeysuckle family, its scientific name combines the Greek terms "hepta" (seven) and "codium" (poppyhead), and when translated from the Chinese name becomes "seven-son flower from Zhejiang." There is concern that it may now be extinct in its original Chinese habitat.
Heptacodium is generally offered for sale as a multi-stem shrub, and it can be trained to grow as a single trunk or low-branched tree, well suited for small spaces. Ultimately reaching about 20 feet, it can grow as much as 3 feet in a single year, and its angular branches are readily pruned to shape when young. Its shiny, downward-pointing, heart-shaped curved leaves emerge early in spring (by late April in Hopkinton), becoming dark green and remaining pest-free all spring and summer. Autumn foliage is yellow-green with silvery undersides, holding into November.
It thrives in full sun or light shade in New England soils without much care, even in dry conditions, once established.
In Hopkinton, the fragrant creamy-white flowers open progressively in early September in groups of seven, clustered at the ends of the current year's growth, and persist for two weeks or more, attracting butterflies and bees. As the flower petals drop, a unique display of red-purple begins, as the bases of the flowers (calyces) expand to surround the developing seeds. This color is the most spectacular feature of this plant (particularly when back-lit by the sun), easily surpassing the beauty of the flowers and intensifying for many weeks, until the fruit matures or frost ends the season.
During winter, the exfoliating papery, whitish, ginger- and grey-colored bark shreds attractively in narrow strips from the stems and trunk, exposing the smooth, blond-tan color beneath. This feature alone qualifies Heptacodium as one of the most attractive choices for the winter garden. Sited against a background of dark green or blue conifers, or alone in the center of the garden surrounded by snow, it draws every eye.
Based upon at least 20 years of experience, experts consider Heptacodium to be perfectly winter hardy in Zone 5, showing no dieback or stem damage from cold temperatures or wind exposure.
The market availability of seven-son flower plants has increased significantly in recent years, and even large plants are readily available at many garden centers. Horticulturists who appreciate the value plants like this afford are excited about offering it to their clients. But, as with many newer plants coming to the market, consumers tend to be skeptical about unfamiliar products, and this is a perfect example.
This autumn, take advantage of this opportunity and choose a spot for Heptacodium in your yard - you'll be rewarded with many years of all-season enjoyment.
R. Wayne Mezitt is the chairman of Weston Nurseries of Hopkinton and a Massachusetts certified horticulturist. He has served as president of the Massachusetts Nursery and Landscape Association, the New England Nursery Association and the American Nursery and Landscape Association, based in Washington, D.C.