Garland Spirea
Spiraea arguta
Rosaceae · broadleaf deciduous shrub · introduced
Last updated
Data Maturity Baseline
This profile contains verified botanical data. Regional field notes and expert review are in progress.
Quick Facts
Height
5–6 ft
Light
Full Sun to Shade
Hardiness
Zone Zones 4a–8b
Phenological Calendar
As of April 29, 2026, Puget Sound stations range from 1558.2 to 1719 GDD₃₂. Garland Spirea has passed 'first bloom' (1391 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 29, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,719 | 'First bloom' | — | — |
| Seattle / UW | 1,676 | 'First bloom' | — | — |
| Kent / Auburn | 1,670 | 'First bloom' | — | — |
| Olympia / Tumwater | 1,626 | 'First bloom' | — | — |
| Bellingham / Whatcom | 1,615 | 'First bloom' | — | — |
| Tacoma / Puyallup | 1,595 | 'First bloom' | — | — |
| Sequim / Rain Shadow | 1,558 | 'First bloom' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Full bloom' BBCH '65' | 923 | '' |
| ● 'First bloom' BBCH '61' NOW | 1391 | '' |
Source: 'Master catalog (OSU, UMD), GDD50 base' About GDD₃₂ →
Season tracker for Kent / Auburn as of Apr 29, 2026. Predicted dates use 16-day weather forecast through May 15, 2026, then climate normals.