Rose
'Leaf emergence'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.
Plant Profile
Size & Form
Site Requirements
Ornamental Interest
Field Observations
Active Conidial Spread
Uredinial Stage (Summer)
Peak Population & Dispersal
Active Spread & Lesion Expansion
+ 4 more — see full disease and pest lists below
Diseases: Regionally Documented (11)
Pests: Regionally Documented (15)
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Rose has passed 'leaf emergence' (730 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,673 | 'Leaf emergence' | — | — |
| Kent / Auburn | 2,665 | 'Leaf emergence' | — | — |
| Seattle / UW | 2,610 | 'Leaf emergence' | — | — |
| Olympia / Tumwater | 2,570 | 'Leaf emergence' | — | — |
| Tacoma / Puyallup | 2,535 | 'Leaf emergence' | — | — |
| Bellingham / Whatcom | 2,533 | 'Leaf emergence' | — | — |
| Sequim / Rain Shadow | 2,436 | 'Leaf emergence' | — | — |
View full calendar (3 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Bud break' BBCH '07' | 730 | '' |
| 'Fall color / leaf senescence' BBCH '93' | 730 | '' |
| ● 'Leaf emergence' BBCH '11' NOW | 730 Observed | '' |
Source: 'NPN citizen science observations (WA+OR), n=20, median. services.usanpn.org' About GDD₃₂ →
Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.