Struggling dogwood tree
We have a large native dogwood that flowered and looked beautiful a month ago, but now has diseased-looking leaves that are shriveling and dropping. Is this a fungus? Or sun stress? Any help in how I might treat and save the tree would be greatly appreciated.
Montgomery County Maryland
Your tree looks like it has two diseases. The leaves at the top of the first photo clearly exhibit the muted discoloration of powdery mildew. This has become a huge problem on dogwoods in the past few years. It doesn't kill, but it weakens the tree (and looks bad). Here is a link to our website for help with that: Powdery Mildew in Trees and Shrubs
The leaves lower in the same photo appear to have anthracnose, a fungal disease. Please read our information about that closely. Examine the underside of the leaf for a positive identification. You can spray a fungicide in the fall, but the timing is crucial, so follow the directions and other guidelines carefully: Dogwood Anthracnose
With that information, there is also a link to our publication on anthracnose which is good to read.