Brewer's Oak
Quercus garryana var. breweri
Fagaceae · broadleaf deciduous shrub · native
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Quercus garryana var. breweri (Fagaceae) is the shrub form of Oregon white oak. It grows only 5 to 6 feet tall, forming a low, spreading thicket on dry, rocky sites. The leaves are similar to the tree form but smaller.
Brewer's oak inhabits dry, exposed sites at higher elevations than the tree form. It grows in full sun on well-drained, rocky soils with minimal water needs. The dwarf habit makes it potentially useful for native-plant gardens where space is limited. Hardy in Zones 3b to 8b.
Quick Facts
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Brewer's Oak has reached 'leaf emergence' (1514 GDD₃₂) and is approaching 'flower buds visible', predicted around Apr 26.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,593 | 'Flower buds visible' | 'First bloom' | 1 |
| Seattle / UW | 1,554 | 'Leaf emergence' | 'Flower buds visible' | 18 |
| Kent / Auburn | 1,537 | 'Leaf emergence' | 'Flower buds visible' | 35 |
| Olympia / Tumwater | 1,505 | 'Full bloom' | 'Leaf emergence' | 10 |
| Bellingham / Whatcom | 1,483 | 'Bud break' | 'Full bloom' | 12 |
| Tacoma / Puyallup | 1,472 | 'Bud break' | 'Full bloom' | 23 |
| Sequim / Rain Shadow | 1,434 | 'Bud break' | 'Full bloom' | 61 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Bud break' BBCH '07' | 1212 | '' |
| 'Full bloom' BBCH '65' | 1495 | '' |
| ● 'Leaf emergence' BBCH '11' NOW | 1514 | '' |
| ○ 'Flower buds visible' BBCH '51' NEXT | 1572 | '' est. Apr 26 (forecast) |
| 'First bloom' BBCH '61' | 1594 | '' est. Apr 27 (forecast) |
| 'Fall color / leaf senescence' BBCH '93' | 1774 | '' est. May 5 (forecast) |
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 23, 2026. Predicted dates use 16-day weather forecast through May 10, 2026, then climate normals.