Water Birch
Betula occidentalis
Betulaceae · broadleaf · native
You find Water Birch clustered along streams and moist canyons throughout the interior and coastal Pacific Northwest, identified by its glossy black-brown, non-peeling bark and yellow fall color. This native shrub-tree stabilizes riparian banks and persists in wet sites unsuitable for most trees.
Water Birch grows 15-30 feet tall in sun to part shade with high water needs, reaching its best size on consistently moist soils (zones 2a-8b). Fast-growing with short lifespan, it suits riparian restoration and wet site planting. The species declines in dry landscapes without consistent moisture. Monitor for rust, canker, and wood decay; bronze birch borer and birch leafminer are predictable pests requiring vigilance.
Quick Facts
Phenological Calendar
| Stage | Typical Window |
|---|---|
| Bud break BBCH 07 | Feb 15-Mar 15 |
| Leaf emergence BBCH 11 | Mar 1-Apr 1 |
| Bloom start BBCH 61 | Apr 1-Apr 30 |
| Bloom end / petal fall BBCH 69 | Apr 15-May 15 |
| Fruit/seed development BBCH 71 | Mar 15-May 31 |
| Leaf drop BBCH 93 | Oct 15-Nov 30 |
| Dormancy BBCH 97 | Nov 15-Feb 28 |