Circumpolar alder group

You will encounter Circumpolar Alder as a shrub or small tree along stream margins and moist meadows from the coast to alpine areas in the Pacific Northwest. Its smooth lenticeled bark and distinctive catkin flowers signal its presence in riparian zones throughout cooler elevations.

This nitrogen-fixing native thrives in moist to wet soils, part shade to sun, and tolerates poor soils that many landscape plants cannot. Growing to 32 feet in ideal conditions, it reaches mature size quickly with moderate vigor. Watch for catkin hypertrophy, rust, and various fungal diseases that occur regularly in the PNW; leaf-feeding insects like tent caterpillars and fall webworms are also common.