A close look at Alnus hirsuta reveals attractive pink-tinged male and female catkins.
It is easy to overlook the alders for much of the year, but during autumn and winter they delight with their delicate catkins. In all species male and female catkins are borne on the same tree. The male catkins of Alnus hirsuta are much more obvious, extending to 4cm in length, while the females reach only 1cm, and are only spotted upon careful examination. This is a hardy species growing to 20m in height, and occurring in north east Asia. It prefers moist conditions, but grows well in ordinary garden soils. It was originally introduced into our gardens from Japan in 1879 by the plant collector Charles Maries, who collected for the renowned nursery Veitch and Sons.