Leaf growths

Asked August 4, 2016, 4:19 PM EDT

Any idea what these are? I think it's a cherry or black cherry tree, here outside Boston Massachusetts

Suffolk County Massachusetts

1 Response

Hi,

According to our plant pathologist, Joan Allen:

This is a leaf rust. On cherry it would be caused by a rust fungus in the genus Tranzschelia. Not much info online. Symptoms usually develop about two months after flowering. The structures on the leaf are spore producing uredinia. Control is with fungicides if needed. Here’s a good home orchard fact sheet from NH.

https://extension.unh.edu/resources/files/Resource005256_Rep7402.pdf