Q: My oak is turning brown and dropping leaves earlier than normal (late September). What could cause this beside drought?
A: Art Morrist, a certified Arborist with Bartlett Tree Experts, says: “It’s possible that late-season browning on oaks could be associated with Bacterial Leaf Scorch (BLS). This is a bacterial infection of the tree that manifests in the later summer as browning around the edges of the leaves. BLS is most common on red oaks; the easiest way to tell the difference between BLS and normal browning is that there will always be a yellow stripe between the green and brown part of the leaf if the tree is infected with BLS.”