A fast-growing, nitrogen-fixing small tree or large shrub with smooth gray bark and oval, serrated leaves. It produces hanging catkins in spring, providing early-season interest.
| Tree | |
| Alnus | |
| Alder | |
| Zone 2 | |
| 4-6+ hours | |
| Moist, well-drained to wet soils | |
| 15-25' | |
| 10-15' | |
| Salix, Cornus, Betula, Viburnum |