Q.The Leaves On One Branch Of My Morello Cheery Tree Are Enlarging And Turning Yellow. What Is This And What Should I Do?
This is only affecting one branch. It looks like the leaves are actually changing shape (they are much larger than other leaves and you can see leaves undergoing the change). The affected leaves are more yellow, larger in size and brown around the edges.
Certified GKH Gardening Expert
It looks like new growth attempting to come out, but it is heavily infected. This is usually caused by wet soils, or soil that has not had a chance to dry out between watering.
You will need to treat with fungicides and correct watering habits if possible.
Here are some articles that will help: