This disease is named for the “scorched” or “burned” appearance of the infected areas. The first symptoms appear early in the spring. The bacterial growth seems to favour warm and wet weather. It starts by infecting the flower buds, but it can also infect any rapidly growing shoots or developing leaves. Once infected, flowers and shoot tips wilt and blacken. Later, these areas take on a characteristic hook form. The leaves and berries cling to the branches throughout the growing season and even into the winter.
Chemical applications do not eliminate Fire Blight, however, they do prevent new infections. Bordeaux Mix, which is made of Hydrated Lime and Copper Sulphate, is a recommended product to use for this disease. Because of its safety, Bordeaux Mix has been used for centuries in gardens and orchards. Two applications to the tree canopy will be done in early spring to minimize the damage caused to Mountain Ash Trees by Fire Blight.