This species was introduced from Europe and should not be confused with native alders. The leaf, flower, and fruit are similar to the native shrub alders found along the streams of the Northeast. Black alder is a tree that can grow 60-70 feet tall. The leaf is smooth, 3-5 inches long, with a serrated margin. Small, winged seed is produced in little woody cone-like fruits. The bark is dark brown, with prominent warty strips.
All trees and shrubs respond very strongly to effective control of weeds and sod. Mechanical or chemical controls are acceptable as long as they are used according to the label. Failure to control sod will result in growth reduced by 50% or more.
Betulaceae -- Birch family
David T. Funk
European alder (Alnus glutinosa), also called black alder or European black alder, was introduced to eastern North America in colonial times. This tree ranges in size from a large shrub to a large tree. It has escaped cultivation and grows naturally on lowlying lands. Its rapid growth, tolerance for acid soils, and nitrogen-fixing role make European alder desirable for shelterbelts, reclamation areas, landscapes, and biomass production. It is valuable to wildlife for providing good cover and a source of seeds.