PHYSOCARPUS opulifolius Maxim.
By Thelma Glover
While most American gardners have probably never heard of a ninebark, this shrub and its cultivars are listed frequently in English Garden Books. With its multi-seasonal appeal its easy to understand why the English recognized ninebark’s value as a beautiful garden shrub. Showy upright sprays of clean snow white flowers literally smother the arching branches in April and May very much resembling some of the old favorite, garden spiraeas. Indeed at a glance, ninebark could easily be mistaken for ‘Snowmound’ or x Vanhouttei spiraea so similar in habit and color are the three. In summer, hundreds of fasicles of inflated fruits, to which the scientific name refers [physa (a bladder), karpon (a fruit)], dangle in colorful rosy and tan clusters like short gored square dancing skirts hanging from a clothesline. With a little judicious pruning in late fall, the winter silhouette is very interesting with the bark on the older canes exfoliating into long, buff colored , shaggy strips exposing rich, shiny, dark brown inner bark.
Native to eastern North America ninebark can be found from Quebec to the Florida panhandle and westward to South Dakota and Colorado. It’s usually found growing in moist, rocky or sandy soil along streams, on cliffs or in bogs. The road leading to Linville Falls in western North Carolina is a good place to view it in its native habitat. It is listed in the Georgia Distribution Atlas in a few northern counties and along the Chattahoochee in extreme southwestern Early County.
Description: Ninebark is a medium large multi-stemmed shrub in the Rose family with a height and spread of 6 to 9’. The recurved arching branches are crowded and dense with the older, most vigorous shoots showing heavy exfoliation (hence the common name). The leaves are simple, alternate, and toothed, mostly ovate shaped with those on the large, older branches usually having three lobes and ranging from l l/2 to 2 1/2” long and about as wide. The leaves on the smaller, younger shoots are variable in shape but are much smaller than those on the larger shoots.
The flowers, emerging in mid April in the Atlanta area, are in white, tight, dense coryms on the new season’s growth. The fruit, an inflated capsule, usually 5 to a cluster, forms immediately as flowering ceases, progressing in color from rosy pink to soft buff through the summer until ripening in early fall.
Culture: Ninebark is very adaptable and undemanding only asking for as much sun as possible and average soil a little in the acid range. It’s drought tolerant after establishment and very long lived. It can be transplanted from containers at any time but the ideal time is when it’s dormant. It can grow quite large but is extremely amenable to selective pruning. In fact, crowded canes need to be removed at their origin each winter. Every few years it needs to be rejuvenated by cutting it to within l’ of the ground. Like many plants in the rose family, it can suffer from black spot in extremely hot, humid summers. The following winter might be a good year for complete rejuvenation.
Propagation: Collect the seeds of ninebark in early fall when the capsule turns brown and shows signs of splitting. The seeds are tan colored when ripe. They can be stored dry in a refrigerator in sealed containers for several years or planted in spring in an outdoor bed. Softwood cuttings can be made in early June until late fall. Like most plants in the rose family rooting is fast and about l00%, with or without a rooting hormone. Rooted cuttings grow extremely fast, so a cutting made in midsummer, can be on its way to being a nice 2 x 2’ flowering shrub by the middle of the next summer.
Garden use: Ninebark is perfect in a shrub border with other large flowering shrubs such as Wigelia, Spiraea, Forsythia and Viburnuns. It’s perfect close to a chain length fence where the tallest canes can arch through the holes giving a vine like effect. Several cascading down a bank makes a more interesting groundcover than shore junipers. Plant ninebark in beds with ornamental fruit trees to provide flowering color from February through May. An all white flowering bed planted with ninebark, snowball and double file Viburnums, which all bloom at the same time, would be a welcoming sight in any garden.
Coombes, Allen J. 1994. Dictionay of Plant Names. Timber Press, Portland, OR.
Dirr, Michael A. 1990. Manual of Woody Landscape Plants. Stipes Publishing, Champaign, IL.
Godfrey, Robt. K. 1988. Trees, Shrubs and Woody Vines of Northern Florida & Adjacent Georgia and Alabama. UGA Press, Athens, GA.
Jones, S. B. and N. C. Coile. 1988. The Distribution of the Vascular Flora of GA. UGA Botany Dept.
Phillips, Roger and Martyn Rix. 1991. Shrubs. MacMillan Books, London.