I have a Shumard Red Oak that has been in my yard for 17 years. It has been struggling over the last couple of years. When it comes back in the spring, 1/2 the tree has very green leaves and looks great, the other 1/2 has very pale leaves. This year, the leaves on the pale half have brown edges and the leaves on the whole tree are pale. What do I need to do? I don't want to lose this tree.
Shumard Red Oak
Certified GKH Gardening Expert
It is very hard to diagnose tree issues without examining the tree. So, I would recommend hiring a tree expert in your area to look at the tree.
That being said, I know that this is not always possible. It sounds like it is some kind of fungus affecting the tree, but there is also a possibility that it could be a pest. If you treat the tree with both a fungicide and a pesticide, you will treat about 75% of what may be affecting your tree.
Also make sure to practice good tree hygiene and remove and destroy any dead branches and fallen leaves from now through the end of the fall. Pests and fungus can hide on dead leaves and reinfect the tree the following year if they are left at the base of the tree.