Common alder is a not particularly striking but easy-to-grow European native. It is appreciated, however, for its rapid growth and ability to thrive in wet soils where few other trees will prosper.
Description of common alder: The common alder has an upright, pyramidal growth habit reaching about 50 feet in height. It has lustrous, green bark that becomes brown with age. The deciduous, dark green leaves are shiny above and dull underneath, and turn bright yellow in fall. They are oval in outline with a toothed margin. The catkins, although not particularly colorful, add some interest because of their early appearance, often while snow is on the ground. The conelike brown fruits are mostly of interest because they are present throughout the fall and winter, when most other trees are totally barren.
How to grow common alder: The common alder prefers light shade but will tolerate full sun or moderate shade. It also tolerates wet soils but will not grow well in dry ones.
Uses for common alder: NOTE: This tree is invasive in portions of the eastern and central United States. It is one of the choicest trees for wet conditions.
Common alder related varieties: There are several varieties with ornamental leaves, including Alnus glutinosa 'Aurea,' with yellow-green leaves, and A. glutinosa. Alnus rubra, red alder, is native to the Pacific Northwest, California, and Idaho. Plants thrive in wet sites.
Scientific name for common alder: Alnus glutinosa 'Imperialis,' with deeply cut, almost lacy leaves.