Lilac tree dead spots
I have a lilac tree that was planted 8 years ago. The last couple of years random branches within the tree begin to die off at the end of May and gets worse throughout the rest of the summer. Any ideas what might be troubling my tree or what can be done.
Dubuque County Iowa
The dieback could be due to Verticillium wilt. Verticillium wilt is a fungal disease. It can infect over 400 plant species. There are no effective control options.
Verticillium wilt is an educated guess. If you wish a more definitive diagnosis, a plant specimen can be submitted to the ISU Plant and Insect Diagnostic Clinic. Information on submitting plant specimens to the clinic can be found at http://www.ent.iastate.edu/pidc/
Thanks for the information.