Red Alder

Red alder is the pioneer of disturbed soils and early succession in Western Washington, a fast-growing deciduous tree that you find instantly colonizing recently logged or cleared land. The smooth, light gray bark is often nearly white due to lichen growth, creating a striking contrast with the red inner bark exposed at branch scars. The leaves are oval, doubly toothed, and often sticky when young. Male and female catkins appear in early spring before the leaves; the male catkins are long and drooping, the female catkins eventually harden into small, woody, cone-like structures that persist through winter and release tiny winged seeds. The tree reaches 60-90 feet in our climate and forms dense pure stands in wet areas.

In Western Washington lowlands, red alder is nitrogen-fixing, enriching depleted soils and improving site conditions for subsequent species. This rapid growth makes it valuable for short-term screening, watershed restoration, and wildlife habitat, though its short lifespan (60-80 years) means planning succession is essential. The tree demands moist, well-drained soils and performs poorly in dry sites. It is highly susceptible to trunk diseases, particularly bleeding canker and Armillaria root rot, which accelerate decline in older trees. Multiple insects attack it, including alder leafminers and flea beetles that create unsightly foliage damage. Plant red alder with the understanding that it is a temporary element in the landscape, valuable for rapid establishment of structure and nitrogen enrichment, but plan to remove or manage decline within 40-60 years. Its contribution to early-stage forest recovery and wildlife habitat justifies its management challenges.