Watch out for root rots in landscape plants this fall, over winter, and next spring. I have confirmed several instances of trees and shrubs dying from Phytophthora root rot this year already.
One of the potential impacts from the wetter than normal season will be increased chances of root rots or reduction of root systems, especially in areas with high water tables or poor drainage. If trees and shrubs begin to turn brown from the top down during the fall or next spring and no other reason can be found for the decline, check the root systems for rotted roots or lack of a good healthy root mass.
Information from Bob Mulrooney, Extension Plant Pathologist, UD