Common Ninebark
'Full bloom'Physocarpus opulifolius
Rosaceae · broadleaf deciduous shrub · native
Last updated
Physocarpus opulifolius (Rosaceae) is a deciduous shrub native to eastern North America. It grows 5 to 10 feet tall with arching branches and attractive exfoliating bark. White to pinkish flower clusters appear in late spring. The species has become one of the most popular landscape shrubs through its colorful-foliage cultivars.
Common ninebark grows in full sun to part shade on a range of soils. Cultivars dominate the trade: 'Diabolo' (8 feet, deep purple foliage), 'Center Glow' (gold center aging to burgundy), 'Coppertina' (copper-orange new growth), and 'Little Devil' (4 feet, compact purple). Powdery mildew is the primary disease concern. Hardy in Zones 2a to 8b.
Quick Facts
Spring Emergence / Primary Infection
Field Observations
Phenological Calendar
As of May 13, 2026, Puget Sound stations range from 1906.2 to 2098.2 GDD₃₂. Common Ninebark has passed 'full bloom' (1932 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 13, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,098 | 'Full bloom' | — | — |
| Kent / Auburn | 2,089 | 'Full bloom' | — | — |
| Seattle / UW | 2,063 | 'Full bloom' | — | — |
| Olympia / Tumwater | 2,025 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 1,993 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 1,972 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 1,906 | 'First bloom' | 'Full bloom' | 26 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Leaf emergence' BBCH '11' | 1624 | 'Late April' |
| 'First bloom' BBCH '61' | 1697 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1932 | '' |
Sources: 'Field observation, Kent, WA, 2026-04-27' ; 'Master catalog (OSU, UMD), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of May 13, 2026. Predicted dates use 16-day weather forecast through May 29, 2026, then climate normals.