Can I use neem oil for black spots on magnolia tree?

Question

I just purchased a magnolia tree in a container. It has darkening leaves that eventually fall off.

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Answer 1

This may be a bacterial blight so Neem oil would not be appropriate. Remove infected branches if you can without defoliating the whole tree. If it's not severe, it should recover. There are no chemical means to help. You may be able to return it to the store for another.

https://www.gardeningknowhow.com/ornamental/trees/magnolia/magnolia-tree-diseases.htm