Rose
Spiraea douglasii
Rosaceae · broadleaf deciduous shrub · native
Last updated
Douglas spirea, also called rose spirea, is a deciduous shrub native to moist habitats of western North America from British Columbia to California, reaching 3-6 feet tall. It produces narrow, hairy leaves and dense, rose-pink flower spikes appearing in mid- to late summer.
This species thrives in moist to wet soils in full sun to part shade and is hardy to zones 5-8. It spreads vigorously via rhizomes and self-seeding and is useful for wetland restoration, riparian plantings, and naturalized gardens. The plant requires consistent moisture and does not tolerate drought.
Quick Facts
Phenological Calendar
As of April 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂. Rose has passed 'leaf emergence' (730 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,181 | 'Leaf emergence' | — | — |
| Seattle / UW | 1,171 | 'Leaf emergence' | — | — |
| Kent / Auburn | 1,111 | 'Leaf emergence' | — | — |
| Olympia / Tumwater | 1,106 | 'Leaf emergence' | — | — |
| Bellingham / Whatcom | 1,101 | 'Leaf emergence' | — | — |
| Tacoma / Puyallup | 1,075 | 'Leaf emergence' | — | — |
| Sequim / Rain Shadow | 1,070 | 'Leaf emergence' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Bud break' BBCH '07' | 730 | '' |
| 'Fall color / leaf senescence' BBCH '93' | 730 | '' |
| ● 'Leaf emergence' BBCH '11' NOW | 730 | '' |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? GDD₃₂ thresholds from USA National Phenology Network citizen science observations (WA+OR). Season tracker for Kent / Auburn as of Apr 3, 2026. Predicted dates use 16-day weather forecast through Apr 19, 2026, then climate normals.