Hello Perry,

Thank you for reaching out to the UVM Extension master gardener program with your question!

This is a combination of fungal diseases: cedar-apple rust, Marssonina leaf blotch and probably apple scab. All are fungi and have loved all the rain this summer. Commercial growers spray up to 15 times a year to control these but most gardeners manage them by raking and destroying leaves in the fall and pruning trees well to open them up to air and light so the leaves dry quicker. Growing apples in the home garden discusses proper pruning of apples. The fungal diseases won’t kill the tree but can weaken it over time.

Below are some extension resources on these fungal diseases. They discuss integrated pest management (IPM) strategies, symptoms, pruning and raking, as well as go into more details on treatment options.

• Cedar-apple rust: https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/rusts/cedar-apple-rust

• Marssonina Blotch: https://ipm.missouri.edu/MEG/2021/4/marsonina-MW/#:~:text=Marssonina%20leaf%20blotch%20can%20be,and%20applying%20fungicides%20when%20needed

• Apple scab: https://extension.umn.edu/plant-diseases/apple-scab

Thank you,