Northern mountain ash, like American mountain ash, is native to north-eastern North America, where it typically grows along rocky river banks and lake shores. Compared with the native European mountain ash (S. aucuparia), this species is sturdier, with thicker branches and larger leaves. The large corymbs of flowers and bunches of fruit are showy, though the berries themselves are quite small. Together with the large attractive leaves and excellent hardiness, Northern mountain ash has deservedly become widely used in landscaping in Finland.
Northern mountain ash and American mountain ash are closely related, the former having larger leaves, flowers and flower corymbs, as well as growing larger and often single-stemmed. It comes into flower about ten days later than American mountain ash. The end buds of the Northern mountain ash are almost black, very sticky, and hairy at the tip, all distinguishing it from S. aucuparia.Northern mountain ash should be considered as a group, within which individuals differ somewhat depending on their origin. All are apomictic, that is, they produce fertile seed without pollination; this means that all the off-spring from a single tree are identical.