Hi, I have a Catalpa tree that is at least 20 years old. I have noticed over the last couple years that during the summer one side of the tree towards the top looks like someone has sprayed it with a plant killer and the leaves start to curl, turn yellow and fall off. It also has a lot of little branches growing straight up on the older branches that are larger. I had a friend say that the little branches are suckerlings and is the trees last attempt to try and survive but it is dying. Is this true? Is my tree dying? How long will it last?