Because it is occasionally abundant on rocky mountains in Pennsylvania, sweet birch may be valuable for soil protection. On other poor soils, however, such as the excessively dry portions of the Harvard Forest in Massachusetts, sweet birch is partially or completely replaced by oaks and conifers. In New England, the species is fairly common in southern Maine, the highlands of New Hampshire, western Vermont, the highlands of Massachusetts and Rhode Island, and throughout Connecticut. Moist, protected northerly or easterly slopes are considered most favorable for sweet birch in both northern and southern parts of its range. Life History Reproduction and Early Growth Flowering and Fruiting Sweet birch flowers are monoecious and borne in catkins.
Pistillate catkins appear with the leaves and are borne terminally on short, spurlike branches.
Seed Production and Dissemination Seed fall is during mid-September through November. Seed dispersal is normally by wind and seeds may be blown some distance over crusted snow. Nothing is known about quantities of seeds produced or how far they are spread. Under forest conditions, seeds normally germinate during the spring after they are dispersed. Nursery experience indicates that germination may extend over 4 to 6 weeks.