Lilac disease & insect issues
Lilacs are tough shrubs but have their share of disease and insect problems. Most will not kill lilacs, but cause leaf browning and stem dieback. If a lilac has one of the following issues, sanitation can be done from now through fall. Management with pesticides needs to be delayed until next spring.
Pseudocercospora is a fungal disease that causes severe leaf browning late July into early August. …