Brewer's Oak
Quercus garryana var. breweri
Fagaceae · broadleaf deciduous shrub · native
Last updated
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 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂. Brewer's Oak typically reaches 'bud break' at 1212 GDD₃₂, predicted around Apr 8.
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 | Pre-season | 'Bud break' | 31 |
| Seattle / UW | 1,171 | Pre-season | 'Bud break' | 41 |
| Kent / Auburn | 1,111 | Pre-season | 'Bud break' | 101 |
| Olympia / Tumwater | 1,106 | Pre-season | 'Bud break' | 106 |
| Bellingham / Whatcom | 1,101 | Pre-season | 'Bud break' | 111 |
| Tacoma / Puyallup | 1,075 | Pre-season | 'Bud break' | 137 |
| Sequim / Rain Shadow | 1,070 | Pre-season | 'Bud break' | 142 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'Bud break' BBCH '07' NEXT | 1212 | '' est. Apr 8 (forecast) |
| 'Full bloom' BBCH '65' | 1495 | '' est. Apr 22 (avg) |
| 'Leaf emergence' BBCH '11' | 1514 | '' est. Apr 23 (avg) |
| 'Flower buds visible' BBCH '51' | 1572 | '' est. Apr 26 (avg) |
| 'First bloom' BBCH '61' | 1594 | '' est. Apr 28 (avg) |
| 'Fall color / leaf senescence' BBCH '93' | 1774 | '' est. May 6 (avg) |
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.