Oregon White Oak
Leaf senescenceQuercus garryana
Fagaceae · broadleaf deciduous tree · native
Last updated
Quercus garryana (Fagaceae) is a deciduous tree native to western North America from British Columbia south through Washington and Oregon to northern California. It grows slowly to about 80 feet tall with a broad, rounded crown and thick, checked bark. The deeply lobed leaves resemble those of eastern white oaks. It is the only native oak of importance in the northern portion of its range.
Oregon white oak grows in full sun on well-drained soil (pH 4.8 to 6.7) with low water needs. It is moderately drought tolerant and long-lived. The species defines the Garry oak ecosystem, one of the most endangered ecosystems in its native range. It is named for Nicholas Garry of the Hudson's Bay Company. The variety breweri is a shrubby form reaching only 5 to 6 feet. Hardy in Zones 3b to 8b.
Open pasture trees around south Puget Sound develop wide branch angles and prominent branch collars, creating more resilient crotch geometry than forest-grown specimens.
— Chris Welch, ISA Certified Arborist
Plant Profile
Size & Form
Site Requirements
Ornamental Interest
Peak Spore Production and Dispersal
Active Conidial Spread
Active Infection & Secondary Spread
Active Below-ground Growth
+ 3 more — see full disease and pest lists below
Diseases: Regionally Documented (13)
Pests: Regionally Documented (14)
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Oregon White Oak has passed leaf senescence (1774 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 senescence | — | — |
| Kent / Auburn | 2,665 | Leaf senescence | — | — |
| Seattle / UW | 2,610 | Leaf senescence | — | — |
| Olympia / Tumwater | 2,570 | Leaf senescence | — | — |
| Tacoma / Puyallup | 2,535 | Leaf senescence | — | — |
| Bellingham / Whatcom | 2,533 | Leaf senescence | — | — |
| Sequim / Rain Shadow | 2,436 | Leaf senescence | — | — |
View full calendar (5 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| Bud break BBCH 07 | 1212 | — |
| Leaf emergence BBCH 11 | 1514 | — |
| Flower buds visible BBCH 55 | 1572 | — |
| First bloom BBCH 61 | 1594 | — |
| ● Leaf senescence BBCH 93 NOW | 1774 | — |
Sources: USA-NPN fall color (n=12, median GDD₃₂=1774, low confidence - wide range) ; USFS Silvics Manual 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.