Why is plane tree (sycamore) dropping leaves?
30 year old sycamore, in Potomac, MD, very healthy and huge, leaves were not even fully size, prior to recent rain and cold.Lots of Leaves turning brown and falling off tree. Canopy seems greener. Is it just the cold and rain affecting the newly formed leaves? Or disease? Is there somewhere I can bring samples? Is this happening elsewhere in Montgomery Co.
Montgomery County Maryland
This is a disease which widely affects sycamores throughout Maryland to varying degrees each year called Sycamore Anthracnose.
Here is a page about it: https://extension.umd.edu/hgic/sycamore-anthracnose
It is not terribly concerning.