by Jan Cashman 5/27/12
Ninebarks (genus Physocarpus) are easy–to-grow, woody shrubs that have increased in popularity over the last few years. One reason for ninebark’s increased popularity is their stunning leaf colors on graceful, arching branches and great new, compact varieties.
Ninebark gets its name because its exfoliating bark is said to peel off in nine layers. This interesting bark makes it a noteworthy shrub even in the winter when the leaves are off.
Another plus for ninebarks is their extreme hardiness (many to USDA hardiness Zone 2) and tolerance of adverse conditions. Ninebarks are not fussy about soil type; they will grow in alkaline clay soil with a high pH or soils with a lower pH. They can withstand cold and heat and will grow in full sun or partial shade. They are extremely drought tolerant but can withstand wet soils. However, ninebarks have been known to get powdery mildew and they are not deer resistant.
Diabolo (sometimes called Diablo) is a large (8-10’) shrub with red-purple leaves and light pinkish-white flowers that contrast nicely against the foliage. Its size can be controlled by cutting it back to the ground each spring. Use Diabolo as a substitute for Purple Leaf Plum for a reliable purple-leafed plant.
Center Glow ninebark, developed in Minnesota, with 8 to 10 feet mature height, is much like Diabolo except the leaves are a brighter red and the new foliage emerges a glowing yellow-green. To achieve its best leaf color, plant Center Glow Ninebark in full sun. Leaves turn red and yellow in the fall.
Summer Wine is a more compact version of Diabolo ninebark with the same wine-colored leaves. It grows to only 5-6’ and seldom needs pruning. Summer Wine Ninebark has the same delicate, pinkish-white flowers in mid-summer and purple to red leaves in the fall.
Compact Dart’s Gold ninebark has bright yellow foliage—plant one next to a Summer Wine for a great contrast. Zone 2 hardy—it grows to only 4-5’ with white flowers and red fruit.
Coppertina is a new tall (8 feet) but narrow hybrid combination of Dart’s Gold and Diabolo Ninebarks. Coppertina’s leaves emerge an attractive copper color in the spring, transforming to a rich red in the summer. As with the other ninebarks, soft pink flowers appear in mid-summer.
Mallow Ninebark (Physocarpus malvaceous) is a native ninebark which grows to about six feet in height. It is found in west and central Montana and other mountain areas east of the Cascades growing in dry canyons and rocky hillsides and in Ponderosa pine and Douglas fir forests. Native ninebarks are found here in the Bozeman Pass, Trail Creek, and Bear Canyon areas. Three to six foot in height, this native variety of ninebark spreads from suckers. Its green leaves turn brownish-red in the fall.
Ninebark has stunning leaf colors, year-round interest, and toughness in dry conditions and poor soil, and no serious insect or disease problems. You can’t go wrong planting ninebark shrubs!