by Matt Gibson
Ninebark is a deciduous shrub with very attractive foliage. Ninebark reaches maturity at six to 10 feet tall and wide in USDA hardiness zones two through seven. The ninebark plant is known for its distinctive foliage, its peeling bark, and its corymbs of white cup-shaped flowers, which attract bees and butterflies.
Ninebark gets its name for its bark, which can be peeled off in multiple, sometimes nine, thin layers. The dark green to reddish leaves of the shrub form a pleasant-looking cascading mound. The plant flowers in late spring in clusters of white (and sometimes pink) flowers that attracts beneficial insects, and produces a red fruit in the summer that attracts birds. It is also available in dwarf varieties that reach only three to four feet in height and spread.
Varieties of Ninebark
A member of the rose family, which includes hawthorns and several fruit trees and shrubs, ninebark grows in abundance all across the eastern United States. Its reach spreads as far west as the Dakotas, as far north as Canada and as far south as northern Florida. There is one variety that is found in the far west in Oregon and Washington, and also in the Rocky Mountains in Colorado. The ninebark shrub comes in several different varieties, nearly all of which produce white or pink flowers. The foliage of the ninebark shrub cultivars are commonly either yellow or purple. Here are a few of our favorite varieties of each foliage color option:
‘Luteus,’ produces yellow leaves that turn light green or yellowish-green in full-sun exposure. ‘Nugget,’ begins with deep golden leaves that turn to chartreuse as the plant matures.
‘Dart’s Gold,’ produces white flowers in the early summer, that bloom atop bright yellow foliage.
‘Monlo,’ popularly known as ‘Diablo,’ is covered in rich dark-burgundy leaves.
‘Seward,’ or is a medium-sized shrub with purple leaves.
‘Mindina,’ or ‘Coppertina,’ shows off a distinctive coppery-purple foliage that matures to reddish purple leaves.
‘Center Glow,’ is a crossover between the yellow and purple-leaved varieties, as it boasts leaves with golden yellow centers which are surrounded by purple.
Some varieties of the shrub are more compact and smaller than the shrubs listed above. Of the dwarf cultivars, standouts include ‘Seward’ Summer Wine, which reaches only 5 feet and boasts reddish purple foliage with pinkish-white flowers in spring. The ‘Little Devil’ cultivar spreads just 3 to 4 feet around and in height, with deep burgundy leaves that accent its pink blooms.
Growing Conditions for Ninebark
Hardy to USDA zones two through seven, ninebark may have a bit of trouble in the warmer regions of zone eight and nine, but can survive in those regions, especially in a shady location. Ninebark likes a sunny to partially shaded location with plenty of room for the shrub to spread out into the landscape.
Dig a hole that is as deep as the container holding your ninebark, and twice as wide. Carefully place the shrub into the hole, making sure that the crown of the shrub is even with the top of the soil around the planting zone. After planting, gently fill in the gaps with the backfill taken out when digging the hole. Carefully pack in soil around the roots and make sure there are no pockets of air around the root system. Water well until the plant is established.
Care of Ninebark
Ninebark is drought tolerant, and can survive on only occasional waterings and limited fertilization in spring with a well-balanced fertilizer. Aside from occasional waterings and limited fertilization, pruning for shape and inner-branch thinning is all that is needed in terms of plant care. Read more about pruning ninebark in the pruning section below.
Ninebark should be pruned at least once a year, early in the growing season. The best time to prune a ninebark shrub is in the first few days after it flowers, which happens between late winter and early summer, depending on your location. Some gardeners choose to do a second pruning for maintenance early in the summer. After midsummer, ninebark goes into dormancy and should not be pruned, as pruning during the plant’s dormancy can damage it.
Always do pruning with sharp gardening tools that have been sterilized. You can create a sterilizing solution by diluting one teaspoon of bleach in two cups of water. Sterilize your pruning tools before you begin working as well as after every time you cut into a part of a plant you think may be diseased. Make your cuts at a 45-degree angle, and always cut as close as you can to the surface of the ground or the place a stem connects to the main branch, avoiding leaving stumps behind.
First, cut away any branches that are dead, damaged, broken, or diseased. You’ll recognize dead branches by their dried-up, crumbly leaves or flaky bark that looks different than the bark on the rest of the plant. Then remove branches as needed to ensure there’s enough room in the interior of the plant for air to circulate and sunlight to reach the inner foliage. Also remove any spindly or weak shoots—ones that sag or produce fewer leaves than others on the plant.
Your pruning should remove no more than a third to half of your ninebark shrub’s branches and foliage at a time. The resulting pruned shrub should be symmetrical in shape as well as narrower at the top than at the bottom (which allows light to reach the branches at the bottom of the plant). Some gardeners just slightly angle the sides of the shrub, while others prefer to prune their ninebark into a pyramid shape. When you’re done pruning, clean up and discard the trimmed branches along with fallen leaves and any other plant material.
Garden Pests and Diseases of Ninebark
Ninebark is easy to take care of, and most gardeners don’t have to struggle with pests or diseases when they’re growing a ninebark shrub. Although it’s not particularly susceptible to diseases or pests, however, there is a chance of encountering the following issues when you cultivate ninebark.
- Cankers: Cankers are caused by bacteria or fungi; they are open wounds that become infected. Cankers can weaken and kill parts of a plant, causing affected branches or parts of the shrub to break away and fall off (usually during a storm). They look like sunken areas, discolored lesions on the bark in shades of red and brown, that may cause splitting or oozing. Sources of stress for plants, such as being transplanted, battling insect infestation, experiencing sunscald, or being damaged by animals and machinery, can make plants more susceptible to cankers. Proper care and maintenance, as well as avoiding stress on plants, is the best way to prevent cankers. Prune several inches past affected parts of the plant to remove the canker and prevent spread of the disease. Read more.
- Leaf spots: All kinds of things can cause leaf spots, but the most common culprit is fungal infection. Gardeners can identify leaf spot fungal disease by the spots of discoloration on foliage that can start as small as a pinpoint and spread to cover an entire leaf. The spotted area is discolored to black, brown, or red and may have a purple or red border around it. Leaf spot diseases can lead to leaves falling from the plant. It’s unlikely for leaf spot diseases to kill a tree. Stress can increase the risk of infection from insect infestation, poor weather conditions such as drought, or a recent transplanting. A plant that’s already stressed or diseased may die after contracting leaf spot diseases as a result of its combined problems. If a plant in your garden has a leaf spot disease, raking up fallen leaves and disposing of them properly is an important step to prevent spread of the disease. Also ensure plenty of room between the ninebark shrub and other plants and, by pruning, within the ninebark’s branches, to allow air to circulate. Severe cases may require use of a fungicide. Read more.
- Powdery mildew: You can recognize this fungal disease by its trademark powdery white substance containing the spores, which appears on the leaves and stems of affected plants. It may also cause leaves to drop from the plant. High humidity combined with conditions that keep the ninebark’s foliage dry increase the risk of powdery mildew. Reduce the risk of powdery mildew by choosing resistant varieties of ninebark, situating plants in full sun, and ensuring air circulation. One treatment method is neem oil; you can make a homemade spray by combining a liter of warm water with four or five drops of dish soap and a teaspoon of neem oil. Sulfur and potassium bicarbonate are other remedies, and sometimes it’s necessary to remove affected plants from the garden and destroy them. Read more.
Common Questions and Answers About Ninebark
Can ninebark be cut to the ground?
Cutting back all the way to the ground is one method of pruning a ninebark shrub. It’s especially recommended to cut a ninebark back to the ground if the shrub is overgrown and out of control. Even if you’re not clipping every branch, those you do cut should be cut as close to the surface of the soil as possible. Always use gardening tools that are sterilized; you can use a teaspoon of bleach diluted in two cups of water to sterilize your pruning shears and other tools.
Do your pruning early in the ninebark’s growing season before it’s put out too much new growth. Depending on where you live, this window will fall between late winter and early summer. You’ll know it’s time to start thinking about pruning your ninebark when it begins to produce flowers. The next few days after blossoming are the absolute best time to prune a ninebark bush. You may need to do a second maintenance pruning in early summer in addition to the main pruning you’ll do as the growing season begins. Regardless, don’t prune your ninebark shrub after the middle of summer—in midsummer, ninebark begins to go dormant, and pruning during dormancy could damage the plant.
First, remove any branches that are dead, damaged, or broken completely, without leaving a stump behind. You can recognize dead or diseased limbs because the foliage on dead limbs will be dry and crumbly, or the bark might flake off or look different than the healthy parts of the shrub. If you think a section is diseased, sanitize your tools again after each cut you make on a diseased branch.
After removal of dead or damaged branches, move on to thin out any overcrowded parts of the plant. Cut branches off at the base where they connect to the main branch. You want enough space between the branches in the ninebark’s interior to allow air to circulate and sunlight to get through. If foliage is crammed tight even though the branches are well spaced, you may need to cut away leaves or smaller stems to create some wiggle room. If any of the stems look like they’re performing poorly, as in not producing much foliage, sagging, or looking spindly, cut those away as well.
When pruning, make all your cuts at the base of a stem where it connects to the main branch or all the way down to the ground, not leaving stubs behind. Always cut at a 45-degree angle. When you’re done, the bottom of the shrub should be wider than its top so the foliage at the bottom can get sunlight. You can angle slightly toward the top or make the sides steeper and prune your ninebark shrub to form a pyramid. Keep symmetry in mind when you’re working—if you remove a large branch from one side, you should remove about the same amount from the opposite side to keep things even. Unless you’re cutting an overgrown ninebark plant all the way down to the ground, you should remove no more than a third to half of the shrub at a time.
Can you prune ninebark in summer?
Once the ninebark has gone dormant in summer, you should wait to prune it until its dormancy is over. The best time to prune a ninebark shrub is a period of a few days after it begins to flower. Depending on where you live, this will happen between late winter and early summer. After midsummer, the ninebark’s dormancy begins, and pruning during dormancy could damage the plant. You can read more about dormancy in our article “Dormant Plants: Your Top Questions, and Answers.”
Can you transplant ninebark?
Yes, you can transplant ninebark. The best times for transplanting a ninebark shrub are late in fall while the plant is dormant or early in spring before buds emerge. Choose a new location for your ninebark in full sun to partial shade that has well-draining soil. Dig a hole in the new location that’s the same depth as the ninebark’s root ball and twice as wide as the root ball. Before you dig up your ninebark, tie its branches up with twine so they’re out of your way and less likely to be damaged while you work or during the move.
You’ll need to estimate the size of the root ball so you know where to dig when you’re digging up the ninebark shrub. Measure the diameter of the shrub’s main trunk at a height of six inches from the ground. Assume one foot of root ball per inch of the shrub diameter you measured. Then dig up the shrub, putting your spade in six inches farther than the root ball diameter you multiplied to calculate. You will probably cut through small roots that are coming out of the root ball as you dig; this is to be expected. Once you’ve dug all around the root ball, lift the ninebark shrub up and out of the soil, then wrap the root ball in burlap and secure the fabric with twine. Wrapping the root ball keeps it together with its soil and prevents damage to the roots during the transplanting process.
Move the shrub to its new location, then unwrap the twine and burlap from the root ball. Place the shrub into the hole you dug, making sure it stands up straight, and fill the soil in around the root ball and trunk in the hole. When you transplant the ninebark to this new spot, it should be buried to the same depth it was in the previous location. Tamp the earth down with your shovel periodically to get rid of air pockets under the soil. Water the ninebark deeply just after transplanting.
Do you cut back ninebark?
Ninebark shrubs should be cut back at least once per year, and some gardeners do a second pruning as well. The main pruning should occur within a few days of blossoms emerging. This will happen sometime between late winter and early summer, depending on where you live. If a second round of pruning is needed, it should happen in early summer. After midsummer, ninebark should not be pruned as it will be in its dormant period, when pruning can cause damage. Always prune with sterilized tools. You can make a sterilization solution by diluting a teaspoon of bleach in two cups of water. You should sterilize your pruning tool before you begin and also after every cut into an area of the plant you suspect may be diseased.
First remove any dead, broken, damaged, or diseased branches. Then cut to create space in the inside of the shrub for air to circulate freely and sunlight to reach the interior branches. Also cut away any stems that look weaker than others, have less foliage, are limp, or sag. If a ninebark shrub is extremely overgrown and the gardener wants to gain control and start fresh, they can cut the ninebark all the way down to the ground. With all your cuts, go in at a 45-degree angle, and cut as close to the surface of the ground or the main connecting branch as you can. Don’t leave stubs behind. The top of the ninebark plant should be narrower than the bottom, either slightly so or in a more exaggerated pyramid, and the shrub’s shape should be symmetrical. You should remove no more than one third to half the plant’s branches and foliage during any one pruning session.
Do ninebark plants lose their leaves?
As a deciduous shrub, ninebark will normally lose its leaves in the wintertime during its dormancy period. The ninebark shrub’s bark may also peel, which is one of the plant’s unique features. Unless the ninebark shrub is losing its leaves outside of the winter dormancy period, dropping leaves is no cause for concern.
Does ninebark bloom on old wood?
Yes, ninebark blooms on old wood. This means that when the ninebark goes into bloom, the flowers appear on parts of the branches and stems that grew the previous year—not on the new growth from the current year. You can identify old wood on your ninebark shrub by looking for a vegetation bud scar that encircles the plant’s stem. This vegetation bud scar shows where the tip of a branch used to be. In a previous growing season, that branch tip budded and started to grow and expand, leaving a scar where the bud scales fell off as the new growth emerged.
Does ninebark grow in the shade?
Ninebark can be grown in locations that get a range from full sun to partial shade.
Does ninebark need full sun?
You can grow ninebark in full sun, but it can also be cultivated in areas of partial sun or partial shade.
How do you care for ninebark?
Plant ninebark in a moist soil that gets good drainage; ninebark is not particular about soil type, but it thrives best in moist areas, such as near streams or ponds. Keep the moisture level high for your ninebark shrub if it’s not near a water feature by hydrating the plant frequently, especially in its first year of growth. Provide about one inch of water each time you water your ninebark. After its first year, the ninebark can tolerate dry conditions better. In spring when buds begin to emerge, it’s time to feed your ninebark shrub with all-purpose fertilizer. Follow the manufacturer’s instructions for dosage and application. Prune your ninebark shrub within a few days of flowering, and you may wish to prune it once again in early summer. Do not prune after midsummer when the plant goes dormant, and scale back the water you give your ninebark shrub during its dormancy as well.
How do you fertilize ninebark?
When new growth begins to sprout in the spring, it’s time to fertilize your ninebark shrub. Use an all-purpose fertilizer, and apply it according to the directions on the package.
How tall do ninebark grow?
Ninebark shrubs can grow to reach heights between six and 10 feet tall when they get proper care and grow in an appropriate climate for their needs. However, some varieties of ninebark are designed to be smaller, such as “Little Devil,” which maxes out around three or four feet.
Is ninebark a perennial?
Ninebark is perennial, which means it lives through the winter in the appropriate climate. Ninebark is hardy to USDA growing zones 2 through 7. You can learn more about perennial plants in our article “Annuals vs. Perennials: What Is the Difference?”
Is ninebark an evergreen?
Ninebark is a deciduous shrub, not an evergreen, which means it loses its leaves during the winter dormancy period.
Is ninebark fast growing?
Ninebark is a quickly growing shrub. In fact, these plants grow so quickly that a ninebark can reach its full mature height in just one year of growth.
Is ninebark native?
The ninebark shrub, Physocarpus opulifolius, is native to central and eastern North America.
What does a ninebark bush look like?
Ninebark’s most distinctive feature is its bark that peels off during the plant’s dormant period in winter. The plant has a mound-like shape, and foliage cascades from it with leaves in hues of dark green or red. The ninebark shrub produces clusters of white or pink blossoms, which bear red fruit that attracts birds at the end of summer and beginning of spring.
When can you transplant ninebark bushes?
There are two ideal times to transplant a ninebark shrub. The first option is to transplant late in the fall while the ninebark shrub is in its dormancy period. The alternative time for transplanting ninebark is in early spring before buds sprout from its branches and new growth begins.
Why is it called ninebark?
The ninebark plant derives its name from its distinctive bark, which during the winter dormancy, peels off in layers—perhaps nine layers, in some cases.
Will deer eat ninebark?
Deer do not normally eat the foliage, bark, or other parts of ninebark shrubs.
Will rabbits eat ninebark?
Rabbits and other animals do not normally consume any part of the ninebark plant.
Want to learn more about growing ninebark?
Better Homes & Gardens covers Ninebark
The Barn Nursery covers Ninebark
National Gardening Association covers Did Ninebark Survive Winter?
National Gardening Association covers Ninebarks
Garden Design covers Growing Ninebark
Gardenerdy covers Ninebark Shrubs
Gardening Know How covers Growing Ninebark Shrubs
Gardening With Charlie covers Growing Ninebark
Hawks Landscape covers Ninebark: Pruning, Water Care and Fertilizing
SFGate Homeguides covers Growing Ninebark
SFGate Homeguides covers How to Prune Ninebark Shrubs
SFGate Homeguides covers How to Plant Summer Wine Ninebark
SFGate Homeguides covers Trim Ninebark Bush
houzz covers Rabbit Preferences for Winter Food
wikiHow covers Pruning Ninebark
Missouri Botanical Garden covers Ninebark
The Morton Arboretum covers Common Ninebark
Oregon State University covers Ninebark Powdery Mildew
Prairie Nursery covers Ninebark
University of Vermont Extension covers Ninebarks
the Spruce covers Common Ninebark
Virginia Native Plant Society covers Ninebark
I wish to grow out seeds of Physocarpus opulifolius. Do I need to presoak aged seed (2-yrs old) and then cold stratify seeds for how long a time?