The female catkins are erect on the stems which develop into drooping, stalked cones with many small nutlike winged seeds. The trunk is dark, rough, and irregularly broken by shallow fissures. Gray birch reproduces mainly by seed. It begins producing seed at 8 years of age with abundant seed crops every year. The seed crops germinate readily.
Gray birch sprouts from the stump when cut or following fire.
Gray birch is found on a wide variety of sites. It grows best on moist, well-drained soil along streams, ponds, lakes, and swamps but also grows on dry sandy or gravelly soil. Obligate Initial Community Species. Gray birch is a pioneer species. It is an early seral species in oldfield succession or following clearcutting in northern hardwood forests.