Hazel Alder is a fast-growing, deciduous shrub with a tendency to form thickets. It is monoecious (separate male and female flowers appear on the same plant). The greenish male catkins and reddish female catkins bloom March-April. The female catkins are followed by woody, cone-like structures containing the seeds; the “cones” turn a maroon color in fall and persist into winter. A variety of bird species eat the seeds. Fall foliage is yellow-orange. It prefers moist to wet soils, and is flood-tolerant. It grows naturally along stream banks and swampy areas. Alder is a nitrogen-fixing species, adding nutrients to the soil. For these reasons, Hazel Alder is planted as a pioneer species for revegetating disturbed areas along streams or ponds. It can also be used in mass plantings for erosion control or to restore wetlands.