Kwanzan Cherry Tree problem
Hello- We have 2 Kwanzan Cherry Trees which are 8 or 9 years old. The leaves, particularly on one, are starting to turn yellow and drop prematurely. The lower leaves are mostly affected, and some have brown spots or look like they are being eaten, but we haven't seen any bugs. The bark is split on both trees and there is a fungus-like growth on the trunk. We were told by a professional landscaper that this is common and it's nothing to worry about, but I don't want to lose my trees! I've attached some photos and hope you can help diagnose the problem and give some advice. Thank you!
Kwanzan cherry has a reputation for being shortlived. We lost ours at the UKREC due to peach tree borers damaging the trunk and roots. Kwanzan cherries get cankers, are susceptible to borers and virus. I would take a sample of a branch with the leaves showing early drop and a branch that appears healthy to the county extension office to be sent to the disease diagnostic laboratory. If they do not find disease then it must be assumed there is borer injury in those cracks. The exudate (gum) is a typical symptom of borer injury. Trees may survive but the damage will affect the structure and appearance. Trunk sprays can protect from further injury but will not eliminate the injury that has already occurred.