Physocarpus opulifolius, commonly called the eastern ninebark, Atlantic ninebark, common ninebark, or simply ninebark, is a deciduous perennial shrub. This shrub belongs to the Rosaceae (rose) botanical family that contains both shrubs and trees, making it a relative of the cherry, apricot, and peach trees. Its genus, Physocarpus, has less than a dozen members, of which most are native to north America.
As shrubs, ninebark species that include Physocarpus opulifolius make for attractive additions to any garden.
Ninebark shrubs don’t only have uniquely exfoliating bark, which is an attractive feature, but these shrubs also flower during the late spring. Their blooms, arranged in spherical patterns, may be white or pink and are equally attractive in either case. Their deep purple foliage keeps these shrubs interesting even when they are not in bloom.
Ninebark shrubs are often planted as part of foundation beds or living hedges, and some can grow to be more than 10 feet (three meters) tall. Others are dwarf species that won’t grow to be more than a few feet tall, on the other hand. They are especially attractive to beginning gardeners because ninebark shrubs are easy to care for — ninebark shrubs look their best when they are mostly allowed to grow naturally, without too much pruning.
About Ninebark Shrubs
- Physocarpus opulifolius is an attractive mound-shaped deciduous shrub that produces delicate pink of soft white flowers, which bloom during the late spring period. The bark of the ninebark shrub peels off in a pattern that visually mimics the shape of the number “9”, giving this plant its distinctive name.
- These shrubs are native to central and eastern North America, where they are commonly incorporated into landscape gardens in hardiness zones two through eight — making them versatile shrubs that are adapted to a variety of soil conditions and climates.
- The fact that the exceptionally charming ninebark shrubs grow notoriously quickly, many species reaching maturity in only one growing season, makes them very appealing to many North American gardeners. Some ninebarks can grow rather big, but their growth can be impeded to make them more compact through pruning.
- Numerous ninebark cultivars have been created to emphasize specific features. They include Physocarpus opulifolius ‘Burgundy Candy’, which has deep crimson leaves and Physocarpus opulifolius, ‘Center Glow’, with leaves that have fresh green centers. Physocarpus opulifolius ‘Dart’s Gold’ is a dwarf shrub that features striking yellow-toned foliage.
- Ninebark has historically been used as a folk remedy to promote a healthy digestive system, in which case a tea is brewed from the shrub’s inner bark.
- Ninebark shrubs are not known to be toxic to pets such as cats or dogs, but because they are considered to be laxatives and are able to induce vomiting, should be kept away from pets if possible.
- The flowers of the ninebark shrub, which are mildly fragrant, are rich in nectar and will attract pollinators. These shrubs are a wonderful choice for people who would like to attract bees and butterflies to their gardens. During the fall, they will also draw birds and small mammals, which are interested in the ninebark’s hardy fruits.
- Ninebark shrubs have adapted to a variety of soil and climate conditions, but these attractive shrubs are unfortunately uniquely vulnerable to aphids. To prevent damage, spraying the plant with neem oil is recommended.
Ninebark Features: An Overview
- Physocarpus opulifolius is a beautiful multi-stemmed deciduous shrub and a perennial. Ninebark shrubs have simple, alternating leaves that are either golden yellow or fresh green during the spring and summer, depending on the cultivar, and will turn a brown, copper, deep yellow, or purple (maroon, burgundy) color during the fall time. The leaves converge into a mound by way of arching branches.
- While the size of a ninebark can vary depending on the exact species, Physocarpus Opulifolius usually grows to around three to 10 feet (three meters) tall and has a nice spread of three to eight feet (one to two and a half meters) wide. Dwarf varieties are also available for people who would prefer a more compact shrub.
- Ninebark gets its name from the distinctive exfoliating (peeling) bark it has, but only mature branches peel. The softer inner bark reveals an attractive red-brown color.
- Because so many different ninebark cultivars have been created, many of which are attractive to home gardeners due to a more manageable and compact size, the perfect ninebark cultivar for you already exists, no matter your aesthetic preferences — you just have to find it!
- Physocarpus opulifolius flowers during the spring or early summer (depending on your region), creating spherical arrangements of white or pink delicate blooms with four to five petals. These three-inch flowers resemble cherry blossoms and have a delicate sweet fragrance.
- Physocarpus opulifolius also bears deep red fruits, in the form of capsules, between late summer and early fall. These fruit capsules are a handsome bonus for people who love to enjoy the sight of birds in their home gardens during the early fall period!
- Ninebark is a dream to take care of — these shrubs generally look best when they are allowed to grow without much intervention. If you do want to prune your Physocarpus opulifolius, do so only after your ninebark has flowered in spring or early summer, because pruning it ahead of this time will prevent it from blooming. Physocarpus opulifolius can sometimes develop leaf spot and mildew. In this case, the affected branches will have to be removed.
- Ninebark plants are versatile. Often incorporated into elaborate landscapes, they can also look wonderful as living privacy gardens, in foundation beds, and in butterfly gardens.
- Ninebark is a fast-growing shrub that can reach full maturity in as little as a year!
Physocarpus opulifolius and its cultivars are fairly undemanding plants that require very little assistance to thrive, as they can tolerate varied conditions.
These wonderful shrubs will reward you with an abundant bloom if you can make sure that your ninebark receives full sunlight, with these plants preferring six hours of bright light a day. If you live in a hotter southern location, however, your ninebark plants will appreciate partial shade in the afternoon, which will protect their leaves.
Temperature-wise, ninebark performs well in a variety of climate conditions. The only conditions they do not cope well in are especially hot and humid ones. In this case, Physocarpus opulifolius becomes vulnerable to fungal diseases. These plants are frost-tolerant and will succeed in colder regions.
While Physocarpus opulifolius prefers neutral or acidic soil types, these plants can also handle alkaline soil. Because they tend to grow along streams and in thickets in the wild, they tolerate moisture well, but do need well-draining soil. Clay or loamy soils are ideal for ninebark shrubs, and these shrubs will thank you by staying strong and healthy if you mulch around the base of the stems every year to assist with moisture retention.
- Red Ninebark (Physocarpus opulifolius) is a hardy deciduous flowering shrub often used in landscaping.
- It gets its name from its bark, which can be peeled off in several thin layers. Ninebark features dark green or reddish leaves that form a nice cascading look.
- It flowers in late spring with bunches of white or pink blooms, and it bears red fruit in late summer and autumn that often attracts birds.
- Growing zone 2-7
- Viburnums are Beautiful Flowering Plants that will add spectacular beauty to any home or garden
Ninebark plants benefit from an organic fertilizer and some compost during the early spring, to assist their growth. However, the fertilizer, which should be sprinkled on the soil around the base of the stems, only needs to be used this one time annually — Physocarpus opulifolius does not need to be fertilizer regularly.
In terms of pruning, it is not strictly necessary to prune these shrubs in most cases, but many people prefer to prune them significantly because of the fact that Physocarpus opulifolius grows shockingly quickly, and may end up using more space than the gardener would like. If you plan on pruning your ninebark shrub, do so after the blooms have subsided. This will simultaneously help you achieve the shape you desire for the shrub and increase airflow.
Likewise, some gardeners prune their binebark shrubs extensively during late fall, in order to protect their Physocarpus opulifolius during the winter, and to encourage the plants to flower more heavily during the new season. Up to a third of the older, mature, branches may be removed if desired, and the shrub will quickly begin growing again.
One further thing you need to be aware of if you are planning to grow Physocarpus opulifolius cultivarsin your home garden is the fact that Physocarpus opulifolius is at risk of developing two separate problems. Ninebark shrubs easily fall prey to aphids, but this can be prevented by misting them with neem oil — or simply by spraying them down with sufficient amounts of water to physically force these little pests off the shrub.
Ninebark shrubs can also develop powdery mildew, leaf spot, fireblight, and other fungal diseases. This tends to happen in conditions that are a little too humid for the ninebark’s liking. In many cases, increasing airflow around the branches greatly reduces the risk of fungal diseases. This is, indeed, the main reason to carefully prune your Physocarpus opulifolius if you are attempting to grow them in slightly more humid areas.
These beautiful shrubs do not need much water to thrive — and Physocarpus opulifolius will tolerate dryer climates like a champ. Thankfully, mature ninebark shrubs also cope well with wetter conditions. Unlike many shrubs, ninebark doesn’t even mind mild flooding or soil that drains quite poorly. Yes, this means that you will not generally need to water your established ninebark shrubs at all. You need to offer supplemental watering only in cases of extreme and prolonged drought. If you need to water other garden plants growing in the vicinity of a Physocarpus opulifolius, on the other hand, these shrubs certainly won’t complain.
Young ninebark plants should, in contrast, be watered regularly; at least once a week, and in hotter climates even twice. After their first year, this will no longer be necessary.
As with other shrubs, ninebark can be challenging to propagate, but it is certainly not impossible so long as you follow the right steps. The easiest way to propagate Physocarpus opulifolius would be through stem cuttings taken during the plant’s dormant stage, in the fall or early winter.
Here’s a look at the process:
- Select several branches from a mature plant, which have grown during the previous spring and summer. Using sharp garden shears, take cuttings of four to six inches (10 to 15 centimeters). As you select the appropriate branches from the parent plant, take care to choose branches that have a minimum of two nodes. You do not need to take stem tip cuttings, and can select a nice branch to then trim it to the right length by making cuts in the top as well as bottom.
- You would be advised to dip the resulting cuttings in a rooting hormone powder, though your Physocarpus opulifolius cuttings may succeed if you skip this step as well.
- These cuttings can now be bundled and stored in the fridge to overwinter them.
- During the early spring, plant the cuttings in a sand and peat medium, where they can be placed under a taller tree that will receive sufficient shade. Keep the soil moist by watering the cuttings every week, or more often if required.
- Roots will start to take hold in a month to a month and a half, after which you can get started with your normal care regimen for young Physocarpus opulifolius
Your new Physocarpus opulifolius can be transplanted to a better location by digging a hole as deep as the root ball, but twice as wide. Your new ninebark shrub will grow rapidly and reach an impressive size within a year.
Ninebark shrubs are beautiful woody perennials that have adapted to a wide variety of conditions. These charming shrubs produce gorgeous flowers, which attract butterflies and bees, during the spring, and grow rather quickly. Whether you’re looking to place a ninebark in your garden to provide an accent, or would like to create a living hedge with Physocarpus opulifolius, these shrubs are easy to take care of.