Last Updated on October 8, 2022 by Real Men Sow
Common ninebark (Physocarpus opulifolius), is a deciduous, flowering shrub that is widely used for landscaping. Its unique exfoliating bark peels away in thin layers as the branches age to give it its name. This shrub, with a coarse texture, is part of the rose family. It also contains hawthorn andspirea. It blooms in late spring with clusters of pink or white flowers. In autumn and summer, it bears red fruit that attracts birds.
Benefits of Growing Physocarpus opulifolius
The attractive native deciduous shrub is named after the extreme peeling of its bark, which is believed to have nine layers. This large, hardy shrub is easy to grow and has dark green leaves. The newer varieties are light green or even burgundy-colored leaves. This makes it an interesting shrub even when it isn’t flowering. The contrast between the rich red rose campion flowers and the ninebark leaves is what I love. In late spring, the flowers appear in clusters of pink or white flowers. Bright red fruits add color to the fall and are a favorite of birds. This shrub is attractive throughout the year thanks to its reddish-colored, peeling bark.
Planting Physocarpus Opulifolius
Ninebark is a hardy plant that can be grown in New England. Ninebark can be grown from plants purchased at a local garden center. They will thrive in full sun to part shade on well-drained soils that are fertile and amended with compost. It is able to withstand wet soils but prefers good water drainage. Plants should be spaced 4 to 6 feet apart.
Make sure to water your new plants regularly. Older plants are more resilient to drought. To preserve soil moisture and keep weeds from growing, add a layer of bark mulch to your spring garden. In spring, fertilize with compost and organic food.
Physocarpus Opulifolius Care Guide
Ninebark is a low-maintenance shrub that requires minimal care and needs to be fed. It can withstand drought and other growing conditions. Ninebark is most attractive when it is allowed to grow and maintain its natural shape. However, proper air circulation can be maintained by trimming the old wood every year. Ninebark flowers on old wood just like hydrangeas. Therefore, it is best to trim the old wood after flowering.
Ninebark plants require the same care as any other woody shrub. Dig the hole twice as deep and as wide as the nursery container. Place the shrub at the ground’s top. Backfill the hole with soil, making sure that there are no air pockets. Before filling the hole, amend poor soil with organic material. After planting, water thoroughly.
Ninebark should be planted in an area that gets full sun or part shade. It will thrive in full sunlight. The shrub needs around 6 hours of direct sunlight per day in northern latitudes. However, it can tolerate some shade in the afternoon for those living further south.
The shrub will tolerate alkaline soils but prefers neutral to slightly acidic soils that drain well. To help prevent weeds and retain moisture, mulch should be placed around the base every year. Ninebark is able to grow in both clay and loam soils.
Ninebark can grow in both wet and dry locations. Although it has a low water requirement, it can withstand flooding and poor drainage. Ninebark can be established in dry areas and is drought-tolerant.
Temperature and Humidity
Ninebark can tolerate a wide range of temperatures and humidity levels within the recommended zones. However, it will not thrive in zones 8 or higher due to extreme heat and humidity from the South. Ninebark can be susceptible to fungal diseases like powdery mildew if it is exposed to high humidity.
Spring is the best season to give your ninebark shrub compost and organic food. Only one annual feeding is necessary. Start by applying fertilizer to soil a few inches from the trunk of the shrub. Then spread it in thin layers around the base.
To maintain the shape of ninebark and improve air circulation, prune it after it blooms, but no later than mid-August. Each pruning can result in one-third of the branches being cut. Focus on damaged or older branches as well as branches that cross or rub against each other.
To encourage more flower and leaf growth in spring, you can radically prune older shrubs. Ninebark is able to bounce back after being pruned.
Propagating Physocarpus Opulifolius
It can be difficult to propagate woody shrubs. Sometimes it takes a year. Ninebark stem cuttings are easy to root. This must be done when the plant is dormant.
Get your pruning shears and rooting hormone (a zippered bag is also helpful). Cut several hardwood branches (not softwood tips), from your shrub in late fall or early winter. Cut about 1/2 inch thick, 4 to 6 inches in length. Every cutting should have at most two nodes (bumps along the branch where the leaves sprout). The bottom should be cut just below the node, and the top should be cut approximately 1/2 inch above the node.
Dip each cut in rooting hormone and secure them with a rubber band. The bundled cuttings should be placed in a bag containing wood shavings or slightly moistened sphagnum moss. Keep the cuttings cool in the refrigerator.
As soon as you can get the ground to work, take the bundled cuttings apart and place them in the soil. Make sure that the tops face up. Place them in the soil so that only the top nodes remain below the ground. Regularly water the cuttings. Your fully rooted cuttings will need to grow for a full season. However, they will be ready to harvest in the late fall or early spring.
Grab a shovel, pruning shears, and a pair of scissors. One of the flexible branches from your mother plant can be bent down so that a portion is buried in the soil. The tip of the branch will remain exposed. Once secured, the buried section will start to sprout roots from its nodes.
Once the branch has established enough roots to support its own growth, you can remove it from the mother plant. Then, cut the root and transplant the cutting.
How to Grow Physocarpus Opulifolius from Seed
The best way to propagate the Ninebark shrub from cuttings is by sowing seeds in the fall. You can do this by mixing a mixture of pine bark, peat, sand, and perlite in the spring. Add water until the mixture feels moist. Divide the mixture into five-inch pots. Sow two seeds in each pot at 1/8 inch depth. Sprinkle the mixture on the top and lightly mist it. The pots should be placed outside in a protected, well-shaded area. Keep the soil moist until the seeds germinate. This can take up to three to two months. Once the seeds germinate, you will need to remove the smaller seedlings from each pot. The pots should be brought indoors in the fall so that the baby shrubs can grow outside.
Companion Planting and Design
Ninebark can be used as a foundation shrub, where it will not grow to the point that it blocks a walkway or window. For the best appearance, give it enough room to grow in its arching branch structure. You can grow ninebark along with deciduous shrubs such as spirea and lilac in a mixed shrub border. To show off brightly colored perennials like coneflowers or bee balm, use different colors of ninebarks at the back of a perennial border.
Physocarpus Opulifolius Common Pests & Plant Diseases
Ninebark shrubs can be susceptible to aphids. To control them, spray the shrub with a steady stream of water or mist the shrub with neem or another organic spray. Ninebark shrubs that have been established are usually healthy and free from any problems. Although fire blight, powdery mildew, and leaf spots can occur, they are not usually fatal. To avoid most diseases, you can trim down badly damaged branches.