Spots with cilia-like growth on crab tree leaves

Asked August 14, 2018, 5:41 PM EDT

Today I discovered that all 4 of our crab apple trees have leaves with red spots and white growth in the center of the spot. See the pic attached. What is this and what do I do about it?

Hennepin County Minnesota

1 Response

It appears to be a gall caused by Cedar Apple Rust. I will include a link below for more information. There are some fungicides that can be used to control it (listed in the article), but it's pretty prevalent in our area and bad this year with the wet start to the growing season.