Heptacodium Miconioides, the Seven-Son Flower

A berm blog update

Dave Cantwell —  September 21, 2013 — 17 Comments
PHOTO: Image of bark

The gorgeous, exfoliating bark of Heptacodium miconioides looks stunning year-round.

Are you looking for a plant that offers some “wow” at the end of the season? That particular something that offers color, and maybe even more? Here’s something on steroids: Heptacodium miconioides.

This large shrub or small tree (15 to 20 feet tall on average), native and rare in the wild in China, was successfully reintroduced to western horticulture in the 1980s, and its popularity has come to span the globe for good reason: this is not just a brilliant autumn performer—it’s a year-round beauty! I suppose we can start the story when this ornamental shrub is dormant in the winter, with its striking exfoliating bark peeling off of nearly every branch in tan, cream, or light brown ribbons or patches, revealing the underlying tissue that has developed into a wash of many colors: vertical striations of creamy white, deep yellow, green, tan, bluish-green, olive green, brown, ochre, and even rust; more so as the plant ages. But that’s just the beginning of the show.

PHOTO: Heptacodium miconioides in flower

The Latin Heptacodium means “seven flowers,” hence its common name “seven-son flower”— though that’s just the average number of flowers on each shoot.

Heptacodium are among the first to sprout leaves in the spring, and their light green color is especially attractive. Should they break dormancy in an early thaw and the leaves succumb to a return of the cold, do not fret, because they’ll start over again. This plant likes to grow. Once the leaves fill in and the warm weather settles in, you’ll have a beautiful, irregularly umbrella-shaped, dense canopy of long, shiny, deep green leaves. And suckers. Be sure to catch them in late May and cut them off, as they can easily and rapidly form straight whip-like vertical branches that mess up the plan. You may even need to revisit the suckering scene in late summer, as it simmers down and readies to bloom.

Let your Heptacodium establish for a couple of seasons into a V-shaped, multistem plant, then select three to seven sturdy stems for the plant to stand on, and cut off the rest of the stems, including the suckers. (As we’ve mentioned, this plant likes to sucker. Profusely. Even if it gets run over by an off-road vehicle—and some of ours have—it will sucker back into a strong and proper plant in one or two seasons.) They really like to grow, and with few natural (nonautomotive) pests to disrupt their progress, they’re reliably hardy in the Chicago area’s Zone 5 climate.

PHOTO: Heptacodium miconioides in fruit

It looks like it’s blooming, but this is the fruiting stage. After pollination, the sepals elongate and change from green to dark pink, becoming part of the incredibly showy fruit.

In late summer the plants begin to set up for their flower display, developing whorls of buds at the tips of the branches; these structures form bracts of seven, hence its common name, “seven-son flower.” These open progressively, until the entire plant is covered in a cloud of tiny white blooms that smell somewhat like jasmine or alyssum—a sweet scent, to be sure. As amazing as this display can be, it changes even more. As the small dark fruits (or seeds, or berries) form, the white petals fade, and the corollas (flower petals) form sturdy calyces (a calyx is a specialized petal that wraps around the fruit) that color up into reds ranging from rose to nearly purple; some are even bluish in color, which can last as late as November, when the birds will find these treats and finish them off.

But wait—there’s even more! We’ve come full-circle back to the amazing winter display of that colorful, textural, exfoliating bark. With all of this to enjoy, seriously consider placing one (or more) of these beauties in a highly visible, year-round spot in your garden.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Dave Cantwell

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David Cantwell, B.A., M.S., assistant horticulturist, is responsible for the Garden Wall and Berm along the Edens Expressway. He began working at the Chicago Botanic Garden in 2003 on the grounds crew, became a crew leader in 2004, and moved to the Berm in 2008. Cantwell began teaching Hands-on Gardening in 2005, and has also taught Gardening Techniques and presented pruning demonstrations at the Chicago Flower & Garden Show.

17 responses to Heptacodium Miconioides, the Seven-Son Flower

  1. Thanks for the pruning tips…my 3 are amazing and so wonderfully fragrant
    in flower arrangements.

  2. Might be just what we’er lookin for. First, how does it deal with full shade? Then, where can we find them?

    • Hi Kathie,

      I don’t think that Heptacodium like full shade. I’m hearing that they even get finicky in partial shade. Our plants are in full sun and thrive.

      Planter’s Palette and Fiore are two places where we’ve found them.

      Thanks for your interest!

  3. Unfortunately I have not had the best success with this plant. Stems are very spindly and I don’t see much that I can prune without doing more harm that good. Suckering is the least of its problem. This was its third season, and I am considering taking it out next year. In response to the question about exposure – mine is in part sun, so maybe it does need full sun. I purchased mine at Planter’s Palette in Winfield.

  4. Heptacodium will grow in shade, but doesn’t particularly enjoy it. The best exposure for maximum performance is full sun.
    It can appear a bit unruly for some people, but to each his/her own.
    It is an interesting and underutilized shrub that deserves attention. Used in the right setting it is remarkable.
    Thanks Dave:)

    • Hi Carolyn,

      Sorry about your Heptacodium. After 3 years and little growth, the siting is something to consider, as Planter’s Palette is highly reputable.

      Our plants sit in full sun, and none receive even partial shade, except for a couple in the back row of the grouping, but they’re spaced apart sufficiently to mitigate shade problems.

      Other considerations might be: drainage, general soil quality, planting depth, unusual objects buried in the soil beneath or near the plant. I recently learned of a tree that failed to thrive, and when they dug it up, they found a concrete slab from a broken foundation buried underneath it–we’re talking about a 10’x10′ and foot-thick slab.

      Should you decide to remove it, check the roots if you can. Sometimes a plant–especially a containerized plant–can develop ‘girdling roots,’ which can strangle it as it grows.

      Thanks for your interest!

    • Thx Lynette, Great hearing from you! Yes, this is a great plant that rewards us with a “remarkable” showing year-round.

  5. Just planted this beauty 7 son flower. Do I need to protect it from deer and rabbits over the winter?
    Please advise as I love the one planted it has gorgeous bark that curves. I plan to plant more next
    year. Deer are a problem in the winter here.

    • Hi Julie,
      Heptacodium are remarkably pest-free/resistant and deer do not find them to be tasty. The only interaction deer have would be this time of the year for the males to use the tree trunks for cleaning their antlers. Protection against ‘buck-rub’ is simple: wrap chicken wire or plastic snow-fencing around the exposed trunk, and they will find something else to use. This season is relatively short, and the protection can be removed in February. I’m glad that you’re adding more specimens to the planting–it will look amazing in no time!

  6. Hi Dave, though I’ve closely observed the true flowering of my H. miconioides and also the following “bloom,” I am still baffled by the botany. I’ve observed that the strap shaped red calyces appear early in true flowering as tiny projections peeking out between whatever the green overlapping sepal-like parts are to be called. I’ve made many macro photographs of single buds from week to week and I’m no closer, not yet, to knowing where the parts of the second bloom arise and what to call them. What’s more, I have over the last three years seen nothing I would call a fruit, though I have collected by dissection what might be four seeds, currently stratifying in the refrigerator.

    I’m very much enjoying my long, slow research, in part because I hope to discover something new, and I plan to take many more macro photographs this year of the entire sequence of bloom, perhaps one a day. If you would like to the photographs, I’ll be glad to send them to you.

    One last note: both honeybees and several wasps visited the flowers in crowds this Spring, but I failed to detect the fragrance that you describe.

    • P.S. To my great surprise I discovered two very large specimens of H. miconioides at a friend’s house this past Fall, both in “bloom.” Someone (landscaper, former homeowner) planted them at least twelve years ago, judging by their size and architecture. Does that seem early?

      • Hi Mark,

        Heptacodium bloom in the fall, so your friend’s plants are ‘in sync’ with their proper season.

        I have noticed over the last 7 years that they can fail to produce fruit when they bloom too late in the fall and the early cold of late fall/early winter stops that formation process. The development of the red calyces that you’ve observed are as far as my plants got last fall (2013), before they were frozen out, and in other years I have abundant fruit that the birds can gorge themselves for several weeks.

        Great that you’re so patient in your observations, and if you’d like to share some of your photographs, I’d be pleased to see them, which you can best FWD to: dcantwell@chicagobotanic.org.

        Thx for your interest, and please feel free to keep me updated on your observations.

        Best,
        d.

  7. What is the root system like – greedy? I would like to use the plant to provide some shade in a hosta bed.

    • Great news! Heptacodium are very into sharing and prove to be polite neighbors with modest roots. Hostas will do well as well, enjoying the dappled shade.
      Best,
      d.

  8. We’ve had this plant 8 or 9 years and didn’t know about pruning the straight suckers. Every spring we find many dead straight sticks inside the plant. It is a very big tree, about 15′ high and it blooms beautifully. The tree is on the northeast corner of our front porch and has more leaves on the south side of the plant, not the side that faces the street. That north side of the plant looks funny being so bare. Do you think major pruning will change that situation?

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