It is a small- to medium-sized tree 15–20 metres (49–66 ft) tall with smooth grey bark even in old age, its life span being a maximum of 60 to 100 years.

There are four to six subspecies, some treated as separate species by some authors: Alnus incana is a light-demanding, fast-growing tree that grows well on poorer soils.

In central Europe, it is a colonist of alluvial land alongside mountain brooks and streams, occurring at elevations up to 1,500 metres (4,900 ft).

In the northern part of its range, it is a common tree species at sea level in forests, abandoned fields and on lakeshores.

Its cut branches may be fed to browsing livestock such as cows and goats, then used for kindling, firewood, or light construction - while root systems fertilize adjacent agricultural plots via nitrogen fixation.