How to Plant, Grow, and Care for Ninebark Shrubs
Whether you have an eroding slope, a soggy rain garden, or poor soil, ninebark shrubs are ready to adapt! Former organic farmer Logan Hailey digs into all you need to know about planting and caring for this low-maintenance native plant.
Native plant landscaping is ecologically beneficial, pollinator-friendly, water-wise, and ideal for lazy gardeners who don’t want to spend all summer in their yard. However, some native plants don’t have the gorgeous ornamental appeal of domesticated cultivars. With its arching branches of maple-like leaves and dense white or pink floral clusters, ninebark is an exception! Ninebark shrubs are as beautiful as they are resilient.
Whether you have poor, compacted soil, a wet rain garden area, or an eroding slope needing stabilization, ninebark shrubs are up for the job! These attractive native plants make gorgeous hedges, privacy screens, or standalone specimens. They’re hardy from frigid zone 2 to mild zone 8 and provide valuable nectar for many pollinators, particularly native bees and the colorful ninebark beetle.
Once established, the plants only need a once-annual pruning to keep them looking tidy. Let’s dig into everything you need to know about growing this widely adaptable and resilient native species.
Ninebark Shrubs Overview
Plant Type Native deciduous shrub
Plant Family Rosaceae (rose family)
Plant Genus Physocarpus
Plant Species opulifolius
Hardiness Zone USDA 2-8
Planting Season Spring or fall
Plant Maintenance Medium
Plant Height 5-8 feet
Fertility Needs Low
Temperature -50°F (dormancy) to 80°F (struggles in hot, humid climates)
Companion Plants Spirea, dogwood
Soil Type Poor, clay, sand, loam, slopes
Plant Spacing 4-6 feet
Watering Needs Low
Sun Exposure Full sun to partial shade
Lifespan Long-lived perennial (30-50+ years)
Pests Aphids, spider mites, scale
Diseases Fire blight, powdery mildew
History and Cultivation
Ninebark (Physocarpus opulifolius) is a large deciduous flowering shrub native to central and eastern North America. This rapidly growing plant has become increasingly popular in ornamental landscapes, particularly native rain gardens or sloped areas with poor, compacted, and eroding soil.
In its native range, ninebark grows wild on rocky lakeshores, wetlands, riverbanks, and hillsides. The related Pacific ninebark (Physocarpus capitatus) is native to the western U.S. and offers similar adaptability, resilience, and ornamental value.
What is Ninebark?
Also known as Eastern ninebark, Atlantic ninebark, or simply ninebark shrub, Physocarpus opulifolius is a large flowering, cold-hardy shrub in the rose family. It grows in USDA zones 2-8 and tolerates a wide range of conditions.
The bark peels in colorful papery layers, providing intriguing winter interest and an explanation for the “ninebark” name. In the summer, the shrub blooms with attractive cascading stems of clustered white flowers resembling spirea. These blooms provide important nectar resources to pollinators, including native bees, butterflies, wasps, and beetles.
Why Should You Plant Ninebark?
Ninebark is a native plant that offers many benefits to almost any garden or landscape yet requires very little maintenance. If you want to support native species and reduce your garden labor, this shrub is for you!
In addition to its striking beauty, the large shrub is extremely important to pollinators. Native bees, wasps, flies, and butterflies rely on ninebark flowers for nectar in the spring or summer.
The plant perfectly fills large open spaces with poor soil or nearby allelopathic plants like black walnut. The resilient ninebark can handle drought, clay, compaction, steep slopes, wet rain gardens, and juglone (the chemical produced by black walnut trees).
Why is it Called Ninebark?
Ninebark got its name for its layers of exfoliating bark in shades of light brown, burgundy, and red. However, the story behind the name is less cut and dried. For all variants, the name directly links to the plant’s habit of having multiple bark layers that peel in long strips, but the rationale is different with each one.
The USDA’s NRCS National Plant Data Center indicates that as the bark peels and exposes a new layer, it’s as if the bark had “nine lives.” Other sources suggest there are nine layers of bark, although peeling trees typically regenerate bark layers as the outer ones peel. A few sources indicate that as the bark peels, it forms the shape of a 9, revealing its common name. While we know that its name comes from the bark, the jury is out on the significance of the number 9 to this tree!
The scientific name Physocarpus opulifolius comes from the Greek word physa, meaning “bladder,” and karpos, meaning “fruit.” The drooping clusters of reddish-brown fruit appear autumn and look like small bladder-shaped seed capsules. The fruits look intriguing against the golden-yellow fall foliage and provide food for native birds preparing for winter.
Like most native plants, ninebark is remarkably easy to propagate by cuttings, layering, volunteer seedlings, or root divisions. The plant naturally spreads via underground runners and self-sows a few volunteer seedlings yearly.
Fortunately, despite its easygoing propagation, the shrub is not an aggressive spreader and will not become invasive in your garden. Use these methods to replicate ninebark for wider hedges, denser hillside stabilization, or more ornamental flowers in your landscape.
The best time to take cuttings from the shrub is mid to late summer after the plant is done flowering. You will need to know how to identify a node, which is the location where buds and leaves emerge from a stem.
Nodes are the key propagation point because they are hubs for undifferentiated cells called meristematic tissue. These cells can become any type of plant tissue, but once submerged in water or soil, the node will be signaled to grow into roots.
The cutting process is very similar to other perennials:
- Use sharp, sanitized pruners or shears.
- Find a 4-6 inch section of healthy stem, preferably new growth without any flowers.
- Cut just below a leaf node.
- Remove the lower leaves to expose the node.
- Optionally, dip the cut end in a rooting hormone.
- Plant the cutting in a well-drained blend such as peat moss, sand, and vermiculite.
- Keep the cutting consistently moist.
- Repeat the process for as many cuttings as you’d like.
- Place the plants in a sheltered area with indirect sunlight.
Ninebark cuttings typically take 4 to 6 weeks to root. Gently tug on the cutting and feel for a slight resistance to indicate it has formed roots. At this point, you can transplant into the landscape in late fall.
Alternatively, up-pot to a 5-gallon pot. Allow the seedling to mature for another season, then plant in early spring while the young bush is dormant.
Layering is a propagation method where you bend a low branch to the ground level and bury a section in soil. When the branch forms roots, you can cut it from the mother plant, allowing it to proliferate independently. This expands the footprint of an existing shrub. For example, you may want to laterally layer your ninebark to create a wider privacy hedge.
The best time to layer is in the very early spring when the plant is still dormant.
To layer the shrub:
- Find a flexible, low-hanging branch.
- Make a small cut or scrape off a section of the bark around the middle of the stem.
- Bury the wounded section in soil, but leave the tip of the branch exposed above ground.
- Keep the soil consistently moist, just like when rooting a cutting.
- Wait for the buried section to develop roots.
- Use clean, sanitized shears to the rooted section away from the original shrub.
Ninebark shrubs produce abundant seeds every season, some falling into the soil and germinating into volunteer seedlings. You can dig up these little root balls and transplant them to a desired location, ensuring they have at least 3 to 6 feet of space from neighboring plants.
Provide plenty of water during the first season. Then, the baby ninebarks can typically fend for themselves.
You can divide in the fall or winter. This sturdy shrub produces a hefty basal clump of stems and roots that you can dig up and cut into sections. Use a strong shovel to lift the plant in early spring. Cut the root ball into smaller divisions with a sharp, sanitized saw or loppers, ensuring each chunk has plenty of healthy roots and shoots.
Transplant the root chunks to the new desired location and watch your ninebark collection expand. Provide plenty of water while divisions get established. While some gardeners warn against diving shrubs like ninebark, it is unlikely to cause any major issues.
The best time to plant or move this deciduous native shrub is in the early spring (before it breaks dormancy) or in the fall after flowering. Although ninebarks are incredibly drought-resilient and tolerant of rugged conditions, they still enjoy consistent watering during their establishment phase.
How to Transplant
Select a new location in full sun to partial shade to transplant a store-bought or home-propagated ninebark into. The soil is not super important, but young plants take off more easily in a moderately moist, well-drained setting.
Planting is very straightforward:
- Dig a hole about twice as wide and deep as the root ball.
- Grasp the potted plant from its base.
- Massage the roots to gently remove it from the container.
- Place it in the hole, spreading the roots downward and out.
- Make sure it stands at the same depth it was originally.
- Backfill with soil.
- Water generously and maintain consistent moisture for the first season.
Ninebark shrubs can grow surprisingly fast and large, up to 8 feet tall and 6 feet wide. Providing at least 4 to 6 feet of space between plants you’d like to reach their full glory is important. Closer spacing may be desired for a denser privacy hedge, but the plants mustn’t get overcrowded, especially in humid environments.
How to Grow
Native plant lovers are often proud to be “lazy gardeners” because their gardens require far less effort than many traditional ornamental plants. Ninebark lives up to the easygoing reputation of indigenous species. As long as the plant has ample sunshine and water during establishment, it will mostly care for itself.
Ninebarks enjoy full sun to partial shade, but the floral display is best in full sun. Because the plant doesn’t enjoy hot, humid weather, it appreciates afternoon shade in southern climates. Thanks to its tolerance for juglone, it can even be planted in the partial shade of a black walnut grove where other plants may not grow.
In the far northern stretches of its range where summers are cool, the plant really needs full sunlight with at least 6 hours of direct light per day. The shrubs have disappointing flower displays when they don’t get enough light.
This plant is unique because it can grow in both dry and wet locations and thrives without irrigation in its wild habitat across the entire eastern United States. From streambanks to exposed hillsides, its native range reveals why it is just as suitable for a rain garden as it is for a xeriscape.
Ninebark generally has low water requirements once established. It can handle prolonged drought in clay, dry sand, or rocky soils. It can even deal with poor drainage and occasional flooding.
The most important thing to remember is that young plants still need water to help them anchor their roots. This is especially important in warmer climates where summer rains are sparse. After the first season, the shrub is usually fine to fend for itself.
Few landscape plants are as versatile as ninebark! You can plant this native shrub in heavy clay, loamy beds, sandy soil, or even rocky border areas of your landscape.
It tolerates poor soil but does best in neutral to slightly acidic soil with some drainage. Mulch helps boost organic matter, retaining moisture and suppressing weeds.
Climate and Temperature
Ninebark is resilient and adaptable throughout USDA zones 2 through 8. In its dormant state, it can handle shockingly cold negative temperatures.
In the summer, it prefers milder weather, around 70 or 80°F. Warmer climates may get away with growing ninebark if it has dappled shade, but hotter, humid environments make the plant more vulnerable to powdery mildew and other diseases.
Ninebark doesn’t need much fertilizer if your soil has a fair amount of organic matter or compost. If you want fertilizer for a bigger flower display, use a balanced fertilizer and avoid anything too high in nitrogen. Excessive nitrogen can cause an overgrowth of foliage at the expense of flowers.
It is also important to avoid fertilizing during the plant’s dormant stage in late fall or winter because this can stimulate fragile new growth at the wrong time of year.
Pruning and Maintenance
The only maintenance this plant needs is for aesthetics. Some landscapers prune ninebark after it finishes flowering, but this should only be a light haircut. Be aware that pruning during the growing season may reduce the amount of red capsule fruits the plant produces in summer and fall.
Major shaping into a hedge or mound should happen in late spring. You can use bypass pruners or power shears to shape it into a desirable appearance.
It’s very important to avoid pruning after mid-August, as this can stimulate new growth that will perish in cold weather. If the plant becomes large, leggy, or out of control, you can cut it back close to the ground in late winter. This will trigger it to rejuvenate and grow back in a bushier, more lush form.
In addition to the wild ninebark Physocarpus opulifolius, several cultivars of ornamental ninebarks are bred for unique foliage, color, size, and growth habits.
Popular varieties include:
Diabolo Ninebark (Physocarpus opulifolius ‘Diabolo’)
For a dramatic color addition to your landscape, this variety has deep purple to dark burgundy leaves that create a striking backdrop for the bright white flower clusters that appear in late spring.
Summer Wine Ninebark (P. opulifolius ‘Summer Wine’)
Another dark foliage variety, this burgundy-leaved shrub produces delicate pastel pink and white flowers. It is smaller than standard types but not quite a dwarf, averaging 5 to 6 feet in height.
Coppertina Ninebark (P. opulifolius ‘Coppertina’)
This cultivar has uniquely coppery-orange colored foliage in vibrant hues throughout the summer. In the fall, the leaves mature to dark purple. It grows 6 to 8 feet tall.
Nugget Ninebark (P. opulifolius ‘Nugget’)
If you need a smaller shrub, this dwarf variety has all the resilience of a common ninebark in a more manageable package. It grows to just 2 or 3 feet tall, perfect for patio containers or small yards. The foliage is a pretty bright yellow-green shade, and the flowers are classic white with pink.
This native shrub looks lovely alongside other flowering perennials that can withstand similar soil and moisture conditions.
As ninebark’s most well-known doppelganger, spirea is a fellow rose-family cousin with similarly shaped flowers. Choose varieties like ‘Anthony Waterer’ spirea or ‘Bridal Wreath’ spirea for a visually appealing combo in the landscape. If growing ninebark in a rain garden or poorly drained area, spirea will not do as well.
The classic fragrant flowers of lilac pair very nicely with ninebark for a privacy hedge or layered planting. Lilac enjoys well-drained soil with slightly alkaline pH, so prepare the area for a thriving lilac and let ninebark hang out in the background of a bed.
Dogwoods are a great companion for ninebarks for soil stabilization on slopes. The distinctive red bark and white flowers look beautiful alongside the ninebark’s shreddy cinnamon bark, maple-like leaves, and clustered white blooms. Both plants establish quickly and help hold sloped soil in place, preventing further erosion.
Pests and Diseases
Ninebark shrubs are the host plant of the native ninebark beetle, so if you notice colorful, intricately decorated beetles crawling on the plant, don’t panic! These are not pests, and they provide important ecological benefits.
However, the shrubs can fall victim to aphids, spider mites, and scale insects that you may need to monitor. Fire blight, powdery mildew, and leaf spot may also be an issue in humid or hot climates.
Aphids, Spider Mites, Scale
These sap-sucking insects tend to attack stressed or poorly adapted plants. Ninebark is generally quite resilient and doesn’t need pesticide applications to protect it.
Often, a rough spray of hose water is enough to knock the pests off. However, if the pests begin causing major defoliation, you may need a horticultural soap or neem oil application to prevent colonies from spreading.
Fire blight is a highly destructive plant disease affecting many rose family members, including pears, crabapples, hawthorn, spirea, and roses. Key symptoms include wilting, blackened blossoms, and browning leaves on the ends of shoots. Sometimes, the shoots droop over and look like a fire has scorched them. Cankers develop on older stems and may ooze a brown liquid during summer.
Erwinia amylovora is the bacteria that causes fire blight. It overwinters in cankers and spreads via wind, rain splash, and insects. Prevention is vital, including sanitizing your tools, removing infected branches, and preventing an accumulation of debris near the plant.
Lime sulfur sprays may suppress the blight when shrubs are flowering. You may need to apply a liquid copper fungicide for a major infection.
Ninebarks are notorious for their susceptibility to powdery mildew, which appears as white tips that look like they’ve been dusted with flour. As the disease spreads in high humidity and warm weather, the leaves may become covered in a white coating that hinders photosynthesis and reduces overall plant health.
The best way to get rid of powdery mildew fungus is to use an organic copper fungicide or a neem oil spray.
There are also some resistant cultivars. Wider spacing and full sun plantings are more resilient against fungal infection.
Ninebark is a native deciduous multi-stemmed shrub mostly used in low-maintenance landscapes. Its clusters of white flowers provide ornamental value in spring, and the cinnamon to burgundy-colored bark looks intriguing in a winter landscape.
The fast-growing shrub is especially useful for stabilizing hillsides and preventing soil erosion. It can also be used in rain gardens where other plants may have trouble tolerating poor drainage or excess water puddling.
It isn’t easy to find a plant as easygoing and resilient as ninebark! This attractive shrub can handle intense extremes from frigid USDA zone 2 to warm zone 9. It doesn’t mind overly wet or drought-prone soils, and it fends for itself while providing year-round aesthetic interest.
The most important thing to remember is that ninebark needs full sunlight in northern zones and adequate water to get established. Avoid this plant in hot southern climates.