Alnus rubra, commonly known as Red Alder, is a fast-growing deciduous tree native to the Pacific Northwest of North America. It is well-suited for riparian zones and disturbed areas, often improving soil through nitrogen fixation. Its smooth, grey bark is accented by patches of white lichen, and the leaves are ovate with finely serrated edges. Red Alder is valuable for erosion control and provides habitat and support for wildlife. In spring, it produces subtle catkins that bring seasonal interest. It is an excellent choice for ecological restoration projects.
- Light: Full sun to partial shade
- Water need: Moderate to high; prefers moist conditions
- Growth rate: Fast
- Mature size (HxW): 40–80 ft x 20–30 ft
- Habit: Upright, spreading
- Bloom/interest: Catkins in spring
- Hardiness zone: 5–8
- Soil tolerance: Prefers moist, well-drained soil; tolerates poor soil
- Drought/heat tolerance: Low; prefers consistent moisture
