The buds on my Summer Wine ninebark (Physocarpus opulifolius ‘Seward’) held tight for a long time this spring. The beautiful dark foliage unfurled early along the long arcs of the branches, but the buds were just tantalizing little specks for weeks. In June, they finally burst. It was worth the wait. Now the branches are daubed with blossoms that look like strawberry cream frosting. Each 1½-inch cluster is packed with about 40 tiny flowers, all in different stages of opening—they begin as little pink buds and open with creamy white petals. The cake underneath—Summer Wine’s chocolate-burgundy leaves—will remain when the frosting’s all gone; it provides a delicious backdrop for summer and fall perennials.
Common name: Ninebark
Botanical name: Physocarpus opulifolius ‘Seward’
Plant type: Deciduous shrub
Zones: 3 to 8
Height: 4 to 6 feet
• Sun: Full sun to part shade
• Soil: Average, well-drained
• Moisture: Medium to dry
• Mulch: Mulch to preserve moisture in the soil.
• Pruning: Prune to shape in late spring or early summer, after it flowers. Ninebark is known for its peeling bark, and this trait is most noticeable on the oldest stems—so leave at least a few old ones when you prune.
• Fertilizer: None needed.
• By division.
Pests and diseases
• Vulnerable to leaf spots and fireblight. Reportedly resistant to powdery mildew.
• Common pests include aphids.
• Summer Wine ninebark is a great specimen plant. Or group several together for an eye-catching hedge or screen.
• The species, Physocarpus opulifolius, is native to North America. This gives Summer Wine a tough and hardy lineage. The species is larger; it can grow 10 feet tall and wide, and it suckers profusely.
• If you like the color of Summer Wine’s leaves, consider building a dark-foliage flower bed or garden.
All in the family
• Other popular cultivars of Physocarpus opulifolius include ‘Dart’s Gold’, with bright yellow-green foliage; ‘Monlo’, one of the parents of Summer Wine, which also has dark leaves; and ‘Mindia’, a cross between ‘Dart’s Gold’ and ‘Monlo’, which has coppery-red foliage.
• There are about 10 species of ninebark, all deciduous shrubs.
(Text by Elizabeth Noll, photo courtesy of Proven Winners)