Ninebark - Tree Trek #101
The Washington County Master Gardeners / SMINC Tree Trek now includes some shrubs that are recommended for landscaping favorable to wildlife. Ninebark is one of these (Physocarpus opulifolius).
Here is the image of the shrub you are viewing, as planted in September 2024:
Location: Southeast of the nature center, near Park exit road. GPS 45.00206 N, 92.90382 W
Ninebark are deciduous shrubs with peeling bark and alternately arranged leaves.
Height: 3 to 8 ft Width: 4 to 6 ft
The leaves are palmate with 3 to 7 lobes and often toothed edges. The inflorescence is a cluster of bell-shaped flowers with 5 rounded white or pink petals and many stamens. The fruit is a flat or inflated dehiscent follicle.
Native to northern Kentucky, and from Quebec to Virginia, Tennessee, Michigan & Minnesota. Found in bogs, forests, on moist limestone cliffs, near ponds, creek banks, and even in dry areas of the northern and central U.S. Introduced in 1687.
Flower and Fruit Details
Monoecious flowers in flat-topped corymbs, 1-2″ across, each flower 1/4-1/3″ diameter, 5-petaled, white or w/ pinkish tinge, w/ about 30 purplish stamens. Blooms in May, into June, w/ an unusual fragrance. Fruits are capsule-like, made up of 3-5 inflated follicles, each 1/4″, red or pinkish at first, eventually turning brown, in dense, umbrella-like clusters, in August/September, then persisting through winter until March.
Leaf and Bark Features
Deciduous: Leaves alternate, simple, roundish-ovate, 1-3″ long & half as wide, w/ 3-5 palmate lobes (terminal larger), w/ a serrated margin, yellowish-green in color, changing to yellow to bronze or maroon-purple. Not outstanding. Petiole 1/4-3/4″ long. Foliage usually holds until late October. Notable Bark: Young twigs slender and smooth, w/ 3 distinct longitudinal ridges below leaf scars. Older bark exfoliates in thin strips or papery sheets, somewhat ragged, gray-brown w/ orange-brown inner bark. Supposedly has 9 layers of exfoliating bark, thus the name.
Culture and Care
Prefers full sun and well-drained soil but tolerates occasional drought, wet sites, and even road salt. Tolerates flooding, wet or dry sites, sandy, rocky or clay soils, alkaline pH. Tolerates pH 6.1-8.5. Extremely cold-hardy; Zone 2-7. May get iron chlorosis at high soil pH. Otherwise, does well in low-fertility soils. Easy to transplant. Adapted to tough sites. Resistant to heat, drought and soil compaction. Old plants may be rejuvenated by cutting to the ground in late winter/early spring while still dormant. No serious insect or disease problems, except powdery mildew, which is often a problem.
Colorful Fall foliage
Many different cultivars are available which provide a variety of choices for Fall color displays.
Homeowner’s Corner
Ninebark is a durable landscape shrub that can tolerate a wide range of soils and exposures, making it a valuable plant for wildlife in Minnesota in many ways. It’s also resistant to insects and disease, and can tolerate drought. Uses in the garden: shrub borders, hedges, screens, or erosion control on banks
Native Plant: Ninebark shrub flowers are perfect for enticing local pollinators.
Nectar and pollen: Ninebark flowers provide a food source for many pollinators, including bees, wasps, flies, butterflies, and moths in early spring.
Nesting cover: Ninebark’s dense, arching branches provide shelter for songbirds and other birds, as well as winter cover for pheasants, quail, grouse, and rabbits.
Food source: The seeds of ninebark are eaten by birds, and the foliage provides food for beetles, aphids, plant bugs, and caterpillars that are important for supporting bird populations.
Erosion control: Ninebark’s extensive fibrous roots help stabilize streambanks and shorelines.
Windbreaks: Ninebark’s dense growth makes it a good choice for windbreaks.
Screening: Ninebark can be used for screening in urban areas. ( avoid using invasive buckthorn for this purpose)
Capable of growing in dry or moist soils, ninebark is a shrub well suited to the edge of waterways where conditions may change rapidly from wet to dry. Ninebark is also useful as a windbreak, field border, and for reclaiming degraded soils.
Ninebark prefers full sun to partial shade, has arching branches and can grow up to ten feet tall. Its bark peels off in papery layers, hence the common name “ninebark”. Its flowers have five white petals and grow in flat clusters, blooming in May or June. The flowers turn into a bladder shaped fruit later in the summer. Its alternately arranged leaves are commonly divided into three lobes and have rounded teeth. Two small, pointed stipules can be found at the base of leaf stalks. Leaves can turn a purplish color in fall when they are growing in full sun and soils conditions that are not overly wet.