Ever since I first saw Heptacodium miconioides, or Seven Sons Flower, growing on the Church of Jesus Christ of Latter-day Saints Office Building Block, this unusual plant has intrigued me. I looked at itcarefully, examined the leaves, but came up empty because I could not identify it.
I was serving as a garden guide and they explained that this rare plant was native to China. Peter Lassig, who was in charge of the gardens, had obtained starts to grow there.
My interest was rekindled when I recently visited the Harvard University's Arnold Arboretum in Boston and saw the plant growing there. It is through the efforts of this arboretum and others that we see the plant growing in this country.
Most people are not familiar with this plant, but it seems to grow very well in Utah. I thought I would share some more recent information on how we came to have the plant in this country and what it needs to grow well.
This plant is the only member of the Heptacodium genus. They are related to the honeysuckle shrubs. The plant is native to the Hubei province in western China but there are fewer than 10 small, natural
stands left in nature. Fortunately, it is now widely grown as an ornamental throughout the world.
It was thought to have been "discovered" in 1980 by the Sino-American Botanical Expedition that went exploring after President Nixon normalized relations with China. Seed collected by the expedition were
brought back to the National Arboretum in Washington D.C. and the Arnold Arboretum.
This was widely reported to be a "new" plant that was previously unknown, but records at the Arnold Arboretum showed otherwise. An expedition taken from the Arboretum by E. H. Wilson collected a specimen of the plant in 1907. It was never propagated here so it remained largely unknown, existing only as a pressed herbarium specimen hidden away in obscure cupboards.
The plant itself has several interesting features. It grows as a small tree or as a large shrub. It is deciduous, so it loses its leaves each fall. It typically grows 8 to 24 feet in height, but in Utah they will be at the somewhat smaller size.
One of the features that intrigued me when I first saw the plant was the interesting leaves. They have three prominent midribs instead of the usual single midrib. They are dark green and are somewhat heart shaped.
It is perhaps the flowers that are the most interesting aspect of the plant and give it its common name. The generic name Heptacodium means "seven flowers." If you closely examine the flower head, there will be an average of seven blossoms on each one.
In the late summer or fall, the plant produces large bouquets of fragrant flowers which cover the crown of the plant. Very few shrubs flower at that time in Utah so that makes the plant unusual for our area.
The small, white, five-petaled flowers are fragrant and attractive to butterflies. While they are very showy, the plant offers a continuing show. The small, purplish-red fruits are crowned by five very showy, sepal-like rose calyces. These elongate after bloom and continue to be attractive into November.
Tan bark exfoliates or peels away. That reveals attractive brown inner bark, which provides good winter interest. The plants require some pruning to keep them in bounds and attractive.
Fortunately the plant is easy to propagate. It grows readily from seeds or from cuttings and so it is available from numerous nurseries although finding it locally might be a little more difficult It is featured as a Plant Select choice from Colorado so they are available at nurseries that feature those plants. The plant is cold hardy to USDA Zone 5 and seems to tolerate alkaline soils as long as the pH is not too high.It has medium water needs and is not considered a high maintenance plant.
The plant will grow in the shade but some sources indicate that plants growing in shade do not develop the retained sepals that develop when the white flowers drop.
If you are looking for something with and unusual bloom time and other interesting features, this might be a plant to consider. Find a spot where it can add a special charm to your garden.
Specimens of this plant are growing on the Church Office Building block west of the Joseph Smith Memorial Building, at the Joan Hardle arboretum in Murray Park and at Red Butte Gardens. If you know of other plants in the area, please email me at [email protected]. Please let me know if the plant has the red calyces now.
For more information on the Plant Select program go to plantselect.org. They list nurseries that have the plants available in Utah.
Thanksgiving Point class, Advanced Landscape Design: Learn to design exciting and useful garden rooms that set your landscape apart from the ordinary. This course focuses on using plants to solve problems in the landscape, hardscapes and successful plant arrangement. Basic Landscape Design is a course prerequisite. The class is Nov. 1, 8 and 15 from 10 a.m.-12:30 p.m. and cost is $40. Call 801-768-7443 to register.
Larry A. Sagers is a horticulture specialist for the Utah State University Extension Service at Thanksgiving Point.