Bacterial blight of lilac, also known as shoot or blossom blight, is caused by the bacterium Pseudomonas syringae pv. syringae. The pathogen is capable of causing damage to all types of lilacs including Japanese, Chinese, Persian and common varieties. Some researchers suggest that white flowering varieties may be more susceptible to infection than other varieties. The disease is usually associated with plants that have been stressed by drought conditions, improper fertilization, and/or have been wounded. The pathogen has also been reported on Forsythia, Blueberry, and other ornamental plants.