Common Ninebark (Physocarpus opulifolius) is an underrated native shrub with four-season interest. This native species is a graceful arching shrub with clusters of creamy white spring flowers followed by showy seed capsules and yellow-orange fall color. Winter interest is provided by the exfoliating bark that gives the plant its common name, derived from the appearance of many layers or strips of bark on the stems.
Native songbirds utilize this peeling bark as nesting material and take shelter in the dense branching habit for nesting sites. Common Ninebark is found in our Wisconsin woodlands as an understory shrub as well as in open areas and is adaptable to growing in light conditions ranging from partial shade to full sun. It will reach a mature height of 6’-10’, with an equal spread.
Caring For & Maintaining Your Ninebark
Ninebark is an easy-care shrub. It is very cold hardy and well adapted to growing in our alkaline soils. It will require regular, thorough, watering for the first season when transplanted, but after that will be fairly drought tolerant.
An annual spring application of slow-release, organic fertilizer, combined with deep watering at the base of the plant during periods of drought, will keep your Ninebark vigorous. Plants in good health are best able to resist damage by disease and insect pests. Stressed Ninebark plants can become susceptible to powdery mildew, especially during our hot, humid Wisconsin summer months.
Powdery mildew is a fungal disease that causes white powdery growth on foliage. While it is primarily an aesthetic issue and ordinarily will not harm the plant, it can be unsightly. Since fungal disease treatment consists of prevention, fungicide spray should be applied as soon as the first signs of mildew are seen. There are several fungicides, both organic and conventional, that can prevent powdery mildew. Read more about Insect, Disease & Weed Control.
How Do You Prune Ninebark?
In youth, Ninebark grows in a somewhat dense, compact habit. As it matures it takes on a looser, arching, fountain-like growth form. Minimal pruning is necessary but if it is desired I recommend pruning to maintain the plant’s distinctive form. Achieve this by selectively removing only branches that are older, damaged, crowded, or crossed. This pruning method will also increase air circulation, which will aid in avoiding powdery mildew.
Ninebark in a Nutshell
Mature height: 3′-8’, depending on cultivar
Mature spread: 3′-8’, depending on cultivar
Light requirement: Full sun to light shade
Growth form: Dense, upright, spreading habit. Individual branches arch to the ground in a fountain-like fashion.
Flowers: Abundant tubular flowers in late spring/early summer. Colors include shades of pink, white, and true red.
USDA Hardiness Zone: Zone 4
Especially valuable for:
Foliage color (cultivars)
Shelter and nesting sites for native songbirds
Moderate deer resistance
Common Ninebark is a good choice for naturalized shrub borders
Cultivars selected for the compact habit are good for foundation plantings
Cultivars selected for leaf color can be used as specimens or combined with evergreens or other deciduous shrubs as a color contrast in shrub borders.
There has been much work done among plant breeders to select for new Ninebarks with such garden-worthy qualities as compact size and interesting foliage color. A few of the varieties we grow include:
Physocarpus opulifolius ‘Jefam’ PP23,177
New foliage is a complex blend of autumn-like colors including shades of yellow, amber, and orange that age to bronze and purple in the fall.
Mature height: 5-6 feet
Physocarpus opulifolius ‘Center Glow’ PP16,894
New foliage emerges with a glowing yellow-green center and matures to burgundy. Creamy white flower clusters in spring contrast with the dark foliage. Red, papery fruit clusters in summer.
Mature height: 8-9 feet
Physocarpus opulifolius ‘ZLEYe12’ PP31,198
This one is fun! Foliage is brilliant yellow and contrasts dramatically with the raspberry-colored fruit. Newly introduced in 2019, this plant was developed by Milwaukee native Dr. David Zlesak.
Mature height: 4 feet
Physocarpus opulifolius ‘Seward’ PP14,821
As the name suggests, this selection sports wine-colored foliage throughout the growing season. Pink flower buds open to creamy white flowers on cascading stems.
Mature height: 5-6 feet
Physocarpus opulifolius ‘Hoogi021’ PP27,986
A dwarf form with dark burgundy-purple leaves. Selected for resistance to powdery mildew.
Mature height: 3-4 feet
Physocarpus opulifolius ‘Donna May’ PP22,634
A compact selection with deep burgundy colored foliage.