Quaking Aspen
'Fall color / leaf senescence'Populus tremuloides
Salicaceae · broadleaf deciduous tree · native
Last updated
Populus tremuloides (Salicaceae) is a deciduous tree native across North America from Alaska to Newfoundland and south to Mexico, making it the most widely distributed tree species on the continent. It grows 40 to 50 feet tall with smooth, white to greenish-white bark and nearly circular leaves on flattened petioles that flutter ("quake") in the slightest breeze. Fall color is brilliant gold to yellow.
Quaking aspen is a pioneer species that colonizes disturbed sites after fire, logging, or avalanche. It spreads aggressively by root suckers, forming clonal colonies that can cover many acres and persist for thousands of years. It requires full sun and cool summer conditions; it struggles in lowland heat. Growth is rapid. Hardy in Zones 2a to 8b.
Plant Profile
Size & Form
Site Requirements
Ornamental Interest
Field Observations
Peak Spore Production and Dispersal
Active Conidial Spread
Peak Population & Dispersal
Larval Feeding & Web Building
+ 7 more — see full disease and pest lists below
Diseases: Regionally Documented (17)
Pests: Regionally Documented (14)
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Quaking Aspen has passed 'fall color / leaf senescence' (2294 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 | 'Fall color / leaf senescence' | — | — |
| Kent / Auburn | 2,665 | 'Fall color / leaf senescence' | — | — |
| Seattle / UW | 2,610 | 'Fall color / leaf senescence' | — | — |
| Olympia / Tumwater | 2,570 | 'Fall color / leaf senescence' | — | — |
| Tacoma / Puyallup | 2,535 | 'Fall color / leaf senescence' | — | — |
| Bellingham / Whatcom | 2,533 | 'Fall color / leaf senescence' | — | — |
| Sequim / Rain Shadow | 2,436 | 'Fall color / leaf senescence' | — | — |
View full calendar (5 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 902 | '' |
| 'Flower buds visible' BBCH '51' | 902 | '' |
| 'Bud break' BBCH '07' | 1129 | '' |
| 'Leaf emergence' BBCH '11' | 1417 Observed | '' |
| ● 'Fall color / leaf senescence' BBCH '93' NOW | 2294 | '' |
Sources: 'NPN citizen science observations (WA+OR), n=24, median. services.usanpn.org' ; observation Kent 2026-04-09' 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.