Heptacodium miconioides

Seven-son flower, an unusual member of the honeysuckle family, is a handsome, vase-shaped tree or large shrub that is relatively unknown to most gardeners and professional landscapers.

During the growing season, Heptacodium miconioides is covered with 4- to 6-inch-long, thick, glossy leaves. Flowers appear in mid to late July in tight, whorled sets of seven flowers. This showy arrangement of flowers gives the plant its common name. Flowers last through August or September.

Following flowering, the sepals at the base of the flowers not only persist, but also continue to elongate and turn bright red as the seeds mature. It is a good source of nectar for butterflies in fall.

Soft, tan-colored, striping bark provides winter interest.

Young plants at Holden Arboretum in Kirtland, Ohio, reached 15 feet tall with a 13-foot spread after 10 years. Holden’s largest specimen is planted on the edge of an embankment above a stream where in 12 years it grew to 20 feet tall with an 18-foot spread.

It can be trained as a single-stem small tree to 20 feet tall or higher.

It is hardy in USDA Hardiness Zones 4-9, up to 7,000 feet above sea level.

The plant was discovered by western horticulturists in 1907 in China, but it was not cultivated commercially. A 1980 expedition to Hangzhou Botanical Garden recollected specimens and the plant was introduced by Arnold Arboretum in Jamaica Plain, Mass.

Although seven-son flower has since been grown and trialed at botanic gardens and universities across the United States, it still is relatively unknown in most markets.

H. miconioides is a 2008 recommended plant by Plant Select, a cooperative program administered by Denver Botanic Gardens and Colorado State University in concert with horticulturists and nurseries throughout the Rocky Mountain region and beyond. The purpose of Plant Select is to seek out, identify and distribute the best plants for landscapes and gardens from the intermountain region to the high plains.

Culture notes

H. miconioides is an adaptable and versatile plant that tolerates a wide range of conditions. Although it tolerates moderately dry conditions, it should not be grown entirely without irrigation.

A sandy soil or loam is best. Side-dress with compost and a complete organic fertilizer in spring.

To propagate, sow seeds as soon as they’re ripe. Seeds will germinate after moist stratification without any cold treatment. Alternatively, take softwood cuttings in spring; they root easily.

In late winter or early spring, prune out crossed branches or branches that are growing too tall, to maintain a well-shaped specimen.

The literature cites no serious insect problems. Dieback on large canes could be an indication of susceptibility to canker disease.

In exposed situations, trees may suffer leaf tatter due to wind.

For more: James E. Klett, Colorado State University Department of Horticulture and Landscape Architecture, (970) 491-7179; jim.klett@colostate.edu.

Specifics

Name: Heptacodium miconioides

Common name: Seven-son flower.

Family: Caprifoliaceae.

Description: Lush-looking large shrub or small tree that produces masses of fragrant white flowers in late summer and equally attractive, persistent cherry-red sepals in fall.

Hardiness: USDA Hardiness Zones 4-9.

Landscape uses: Large shrub or small tree, as a centerpiece of the landscape. Shrub border or woodland garden. Excellent as a lawn specimen or accent around a residence.

{sidebar id=2}

- Kevin Neal

March 2008