NOT RECOMMENDED TO PLANT: INVASIVE TENDENCIES. Alnus glutinosa, or European alder, is not recommended to plant, due to invasive tendencies. This species is non-native to Ontario with a natural range in Europe, western Asia, and North Africa, and rarely found in the nursery industry. It prefers moist to wet soils, with a pH between 6.0 and 8.0, with an ideal soil composition being a mix of clay, silt, and sand. It is known to be aggressive and overshadow native trees, altering soil chemistry and biology that makes it challenging for native species to grow. Although it is occasionally planted for soil rehabilitation on degraded sites, it poses a significant threat to wetland and riparian habitats. As an alternative, consider planting Betula papyrifera.