Design

How to Grow and Care for Ninebark Shrubs

Fine Gardening – Issue 202
How to Grow and Care for Ninebark Shrubs
Panther®. Photo: courtesy of Richard Hawke

A low-maintenance native shrub, ninebark grows best in full sun to light shade. Although it prefers evenly moist, well-drained soil, it is adaptable to rocky and clay soils and is drought tolerant once established. Here is more of what you should know about this tough plant.

 


Ninebarks Quick Facts

Physocarpus opulifolius and cvs.

Zones: 2–7

Conditions: Full sun to partial shade; moist, well-drained soil

Native range: Eastern North America

Pests: Aphids

Diseases: Fire blight, leaf spot, powdery mildew

Propagation: Softwood cuttings or root suckers for transplanting


Bark

 

How to Grow Ninebark

Don’t underplay the bark. Ninebark gets its name from the way the older bark splits and shreds into narrow papery layers of slightly different colors. This trait is especially eye-catching in winter and gives the garden interest in the off-season.

Growing Tips:

Ninebark is versatile regarding soil types and exhibits drought tolerance, making it easy to cultivate. These plants usually prefer well-drained, acidic soils and full sunlight. However, I’ve heard they can also grow well in amended clay soils and partial shade. They are known to endure poor soil conditions and flourish in hardiness Zones 2 through 7.

Bloom time

Fruit Flowers and fruit enhance the color show. Clusters of pretty white or pink blossoms appear for a short time in late spring to early summer, followed by inflated fruits that add a spot of red late in the season.

 

Pest and Disease

Aphid Infestation Expect a few pests and diseases. As part of the rose family, ninebarks can experience some of the same problems; fire blight, leaf spot, and aphids are occasionally troublesome. Ninebarks are considered deer resistant, which we all know is somewhat of a misnomer since deer defy such labels. Foliar chlorosis may be a problem in high-alkaline soil.
Powdery Mildew Powdery mildew is less of an issue on newer varieties. I have seen powdery mildew on ninebark foliage so densely fuzzy white that the leaves are barely recognizable as leaves. Mildew has yet to be an issue in our trial; however, ‘Chameleon’, Diabolo®, ‘Morning Star’, ‘Nugget’, Summer Wine®, and Summer Wine® Black have had minor infections. Only ‘Center Glow’ and Coppertina® were severely impacted by mildew in 2020; it was one thing I could not blame on the pandemic.

 


| Maintenance |

Ninebark Pruning Basics

It’s a good idea to cut out dead, crossed, or leggy stems on a ninebark every year in late winter or early spring. Aside from that general maintenance, there are three solid pruning methods you can employ. But keep one important fact in mind before you start: Ninebarks flower on old wood, so any early season pruning decreases the bloom, while pruning after flowering decreases fruit.

 

Method 1

Selectively remove up to a third of the oldest stems each year (in late winter) over a three-year cycle. This is a stepped approach to rejuvenation and improves air circulation, which can help alleviate powdery mildew infections.

Selectively remove up to a third of the oldest stems each year (in late winter) over a three-year cycle.
Illustration: Karalyn Demos

Before
“Before” photo: Danielle Sherry

After
“After” photo: Danielle Sherry

 

Method 2 

Give the shrub a light, postbloom shearing to head back any errant or overly vigorous stems and even out the summer habit.

Give the shrub a light, postbloom shearing to head back any errant or overly vigorous stems and even out the summer habit. 
Illustration: Karalyn Demos

 

Method 3

Renewal or rejuvenation pruning is a good technique for overgrown or scraggly ninebarks. Cutting all stems to the ground in late winter allows you to start over. Plants will be compact for a few years but will eventually reach their full size. Flowers and fruits for the year are sacrificed every time this is done, so do it sparingly. The exfoliating bark on older wood is also less pronounced for several years until stems gain some age.

Renewal or rejuvenation pruning is a good technique for overgrown or scraggly ninebarks.
Illustration: Karalyn Demos


See more

The Best Ninebark Shrubs for the Garden

Brand-New Ninebark Shrubs Showing Promise

How to Prune Ninebark

 

Richard Hawke is plant evaluation manager at the Chicago Botanic Garden in Glencoe, Illinois.

View Comments

Comments

Log in or create an account to post a comment.

Related Articles

The Latest