California Black Oak
Quercus kelloggii
Fagaceae · broadleaf deciduous tree · native
Last updated
Quercus kelloggii (Fagaceae) is a large deciduous oak native to the mountains of Oregon and California. It grows 40 to 80 feet tall with a broad, rounded crown. The deeply lobed, bristle-tipped leaves place it in the red oak group (section Lobatae). Fall color is yellow to russet.
California black oak grows in full sun on well-drained soils at elevations of 1,000 to 8,000 feet. It is adapted to the dry-summer Mediterranean climate of its range. Acorns were a primary food staple for indigenous peoples of California and southern Oregon. Hardy in Zones 7a to 8b.
Quick Facts
Phenological Calendar
As of April 9, 2026, Puget Sound stations range from 1181.7 to 1312.1 GDD₃₂. California Black Oak typically reaches 'leaf emergence' at 3533 GDD₃₂, predicted around Jul 11.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 9, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,312 | Pre-season | 'Leaf emergence' | 2,221 |
| Seattle / UW | 1,289 | Pre-season | 'Leaf emergence' | 2,244 |
| Kent / Auburn | 1,246 | Pre-season | 'Leaf emergence' | 2,287 |
| Olympia / Tumwater | 1,227 | Pre-season | 'Leaf emergence' | 2,306 |
| Bellingham / Whatcom | 1,213 | Pre-season | 'Leaf emergence' | 2,320 |
| Tacoma / Puyallup | 1,198 | Pre-season | 'Leaf emergence' | 2,335 |
| Sequim / Rain Shadow | 1,182 | Pre-season | 'Leaf emergence' | 2,351 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'Leaf emergence' BBCH '11' NEXT | 3533 | '' est. Jul 11 (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 9, 2026. Predicted dates use 16-day weather forecast through Apr 25, 2026, then climate normals.