Sorbus alnifolia, or Korean mountain ash, is a non-native tree species originating from China, Korea, and Japan. It prefers cooler conditions and can have poor performance during hot, humid summers. In addition, it prefers moist, acidic, well-drained soils in full sun. It is resistant to borers that commonly affect other mountain ash species, making it one of the best choices for pest resistance and form. It is not tolerant of air pollution nor street-side conditions or high salt, but can withstand strong winds and is easy to transplant. Sorbus alnifolia drops small fruits and a moderate number of leaves, with the heaviest shedding in the fall.