Sorbus americana, or American mountain ash is native to Ontario with a natural range for eastern North America from Quebec and Ontario to Georgia. American mountain ash is not a �true� ash, and as such is not susceptible to the emerald ash borer. It is best grown in moist, acidic, humusy, well drained soils in full sun. It is not resilient to urban stresses and may be best suited for park and restoration plantings. Young stems and thin bark require protection from winter browsing. The seeds are reported to be poisonous, but the fruits are enjoyed by many birds and mammals. Sorbus americana drops small fruits and a moderate number of leaves, with the heaviest shedding in the fall.