My magnolia tree has developed brown discoloration on the leaves and even darker brown spots. They are not on the back side of the leaf. The tree was planted about 7 years ago.
Certified GKH Gardening Expert
These are fungal spots. This is common, and usually not a big threat to the tree. This will usually resolve itself over time. You can help it along some with some wettable sulfur. Just follow the instructions on the package.
This article will give you more information: https://www.gardeningknowhow.com/ornamental/trees/magnolia/magnolia-tree-diseases.htm