Corylus avellana, or European filbert, is a non-native species from Europe and Asia that produces edible hazelnuts that ripen in late August and September. It prefers moist, well-drained soils, but is fairly tolerant to different conditions. To maintain its appearance and prevent thicket formation, prompt removal of root suckers is necessary. While it�s susceptible to eastern filbert blight and occasional issues like black knot, crown gall, and leaf spot, it remains a productive plant when properly cared for. The tree can be moderately messy with fallen nuts, catkins, and leaves, requiring occasional clean-up. Japanese beetles may also target its foliage, and its pollen and nuts could cause allergic reactions in some individuals.