Another wet, cool, and long Spring! And like last year we are seeing lots of fungus issues promoted by the cool and wet weather. For the most part, it’s been the normal cast of characters like Anthracnose, Discula, Cedar Apple rust, and some root rot issues like phytophora; but then we started seeing prevalent issues with ornamental Cherry trees.
The Cherry trees were showing symptoms of blackened leaves, and open cankers on stems and small branches. The disease and the bacterium on these ornamental Cherry trees were confirmed by Rutgers Diagnostics as Pseudomonas syringae. This opportunistic pathogen attacks a wide variety of woody plants especially when they are damaged by frost or injury. The disease gains entry into the tree through wounds or natural openings.
Although the visual effects of Pseudomonas syringae may vary from year to year based on weather conditions, the trees can “out-grow” the symptoms and become less of an eyesore if steps are taken to help the tree along the way.
What can be done?
First, it is recommended to prune out as much of the infected tissue as possible in the Dormant season, as to not increase the chances of spreading the disease. Secondly, to provide fungicide applications in the Spring to help reduce the impact of bacterial cankers. Lastly, as with most plant issues, keep plants as healthy as you can with proper nutrition to assist in avoiding additional stress.
If your tree is looking “sick” have your Arborist Consultant inspect, properly diagnose and provide treatment options based on the level of decline, and your ultimate goals.