Ash
Sorbaria sorbifolia
Rosaceae · broadleaf deciduous shrub · introduced
Last updated
Data Coverage 4 of 6 dimensions
Quick Facts
Height
6 ft
Spread
9 ft
Growth Rate
Fast
Light
Sun to Part Shade
Soil
Moist
Water
Moderate
Hardiness
Zone Zones 2a–7b
Bloom Time
June to July
Origin
Northern Asia (Siberia, China, Korea, Japan)
Phenological Calendar
As of April 20, 2026, Puget Sound stations range from 1373.1 to 1531.6 GDD₃₂. Ash typically reaches 'first bloom' at 3276 GDD₃₂, predicted around Jun 30.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 20, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,532 | Pre-season | 'First bloom' | 1,744 |
| Seattle / UW | 1,493 | Pre-season | 'First bloom' | 1,783 |
| Kent / Auburn | 1,472 | Pre-season | 'First bloom' | 1,804 |
| Olympia / Tumwater | 1,444 | Pre-season | 'First bloom' | 1,832 |
| Bellingham / Whatcom | 1,417 | Pre-season | 'First bloom' | 1,859 |
| Tacoma / Puyallup | 1,411 | Pre-season | 'First bloom' | 1,865 |
| Sequim / Rain Shadow | 1,373 | Pre-season | 'First bloom' | 1,903 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 3276 | '' est. Jun 30 (avg) |
Range: 2515–2896 GDD₃₂
(6yr)
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Hover over GDD values for source details. Season tracker for Kent / Auburn as of Apr 20, 2026. Predicted dates use 16-day weather forecast through May 6, 2026, then climate normals.
Cultivars (2)
''Bococot'' Cherry On Top™
Cherry On Top™ Sorbaria, Cherry On Top™ Ash Leaf Spiraea
''Sem''
Sem Ash Leaf Spiraea