Decorative crab apple fungus

Asked May 11, 2016, 11:29 AM EDT

I live in a townhome, where we have many decorative crab apple trees. They have the fungus so our assoc had our lawn service spray the trees. We have the trees extensively trimmed this year. How many years do we have to spray our trees? I thought I read someplace that they only needed 3 years straight & then is doing good, didn't need to spray again. Please advise. Thanks.

Dakota County Minnesota crab apple trees

1 Response

Hi, and thanks for contacting AaE.

I don't know exactly which disease your trees are afflicted with so I can't give you a definitive answer, but I can send some fact sheets that explain the various diseases, and make recommendations for treatment protocols:
Apple Scab -
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/managing-apple-scab/

Cedar Apple Rust -
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/cedar-apple-rust-and-gymnosporangium-ru...

Fire Blight -
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/fire-blight/

Powdery Mildew -
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/powdery-mildew/