Alder - Prairie HorizonAlnus hirsuta 'Harbin' The Prairie Horizon Alder, a medium large tree, stands as a beacon of cold hardiness, capable of thriving in both wet and dry conditions. Its upright stature is accentuated by a distinctive light colored bark that beautifully contrasts with the deep green foliage, transitioning to a vibrant gold hue in the fall. Adding to its allure, the Prairie Horizon Alder showcases purple catkins, followed by intriguing brown strobiles that