PHYSOCARPUS: Pacific Ninebark
If you have a naturally-moist area of your garden with space for a largish shrub to settle in and make itself at home, the Pacific Ninebark (Physocarpus capitatus) might be the perfect choice. In the wild it can be found along stream banks, at the edge of moist woodlands and wetlands; it will indeed languish if allowed to get too dry.
Fast-growing up to 12 feet tall and wide, the native Physocarpus' multi-stemmed nature will create a graceful, slightly arching thicket, perfect for a mixed hedgerow or natural, wooded area attractive to birds, providing a good source of cover and protected nesting sites. The upright, graceful shape can be further emphasized by pruning, helping to keep the plant's tendency to sometimes become straggly in check, keep it more full and lush. Its extensive root system also makes it good for those situations needing erosion control, slope or along a waterway.
The slightly crinkled, dark/bright green lobed leaves, reminiscent of currant or maple, is a beautifully textured contrast against that of the reddish-brown, shredding bark.
The clusters of flower buds, with their reddish-pink hue, open to reveal near spheres of tightly packed, tiny white flowers from April to July. What follows are pinkish-brown seed coats that tend to remain on the plant throughout the year, adding more contrast and texture (along with the peeling bark) for winter interest.
Aside from occasional pruning and assurance of sufficient moisture, Ninebark needs little else in the way of care. Virtually pest and disease free, though on occasion it can be troubled by aphids or powdery mildew.
More specifically a right-plant-right-place specimen than some native plants, P. capitatus is full of year-round beauty, and is worth trying to find a home for in your landscape!
Common name: Western Ninebark, Pacific Ninebark
Native Range: Alaska, western British Columbia south to California; in Oregon, found primarily west of the Cascades, though a bit in north-central and far northeast counties.
Characteristics: An upright, thicket-producing shrub that can range in size from 6 to 12 feet tall and wide, depending mostly on amount of sun and water it receives. Deciduous leaves are lobed and toothed, similar to red-flowering currant and reminiscent of maple.
Tight clusters of small white flowers appear in late spring into mid-summer followed by persistent brown seed coats; its reddish peeling bark makes it an attractive specimen in the winter garden.
Culture: Full sun to part shade, moist to fairly wet soil. Requires some pruning to keep its naturally graceful, arching shape from getting straggly.
Pests/Diseases: Occasionally subject to aphids and powdery mildew, but not frequently. Generally trouble-free.