Alnus rubra

Red Alder
Betulaceae
Deciduous, Trees

ALNUS

Moisture-loving trees that thrive in moist or wet soils, even tolerate periodic flooding. Good near creeks and other waterways. Very fast growing. In all species, clusters of tassel-like, greenish yellow male flower catkins give interesting display before leafout. Female flowers develop into small woody cones that decorate bare branches in winter; these delight flower arrangers. Seeds attract birds. Alders need little pruning except to remove suckers, crossing branches, and dead wood.

Alnus rubra

Native to stream banks andmarshy places from Alaska south to Northern California;usually found in areas withmaritime influence. This is themost common alder of lowlandsin the Pacific Northwest. It cangrow to 90 ft. high but is usuallyseen at 45–50 ft. tall and20–30 ft. wide. Attractive barkis light gray and smooth. Darkgreen leaves are rust-coloredand hairy beneath; coarselytoothed margins are rolledunder. Red alder can take brackish water and is useful wherever underground water issomewhat saline. It’s generallydisliked in the Pacific Northwestbecause it is a favorite of tentcaterpillars.