Leaf drop from Yoshino cherry - Ask Extension
I am seeing a lot of green leaf drop from my two Yoshino trees (~20 years old). There has been plenty of rain this year so not drought stress. My ot...
Knowledgebase
Leaf drop from Yoshino cherry #644676
Asked June 02, 2020, 8:11 AM EDT
I am seeing a lot of green leaf drop from my two Yoshino trees (~20 years old). There has been plenty of rain this year so not drought stress. My other trees are not showing this drop, including my Kwanzan cherries in the front. The leaves do have some holes with brown patches. There are many more still on the tree with the same conditions. It doesn't appear limited to just at tips or just interior, seems pretty globally on the tree. I see there are other cherry questions with the same issue, so it must be a broader problem. I found some resources on your website. This is "shot hole" disease? Boosted by the spring rains? And apparently no action to take either; will go away with heat and no effective treatment?
Baltimore County Maryland
Expert Response
You are seeing the symptoms of cherry shot hole disease. Wet spring weather is ideal for the development of this disease and we have had a lot of questions about this recently.
Both a fungus and a bacterium can cause shot hole disease in cherries, and distinguishing between the two pathogens is challenging. Neither will be controlled by sprays applied after symptoms have progressed to this point. Some defoliation also can occur as a result of this condition.
The good news is that trees produce many more leaves than they need to feed themselves via photosynthesis, and in most cases mature trees can sustain some of this damage and recover in future years. No treatment is recommended. Remove and dispose of fallen leaves to reduce fungal inoculum around the planting area. This does tend to be a chronic issue in cherry trees in this area, and it is typically worse in wet weather years.
Here is more about cherry shot hole and how to manage it. https://extension.umd.edu/hgic/topics/cherry-shot-hole-flowering-cherries
Marian
Both a fungus and a bacterium can cause shot hole disease in cherries, and distinguishing between the two pathogens is challenging. Neither will be controlled by sprays applied after symptoms have progressed to this point. Some defoliation also can occur as a result of this condition.
The good news is that trees produce many more leaves than they need to feed themselves via photosynthesis, and in most cases mature trees can sustain some of this damage and recover in future years. No treatment is recommended. Remove and dispose of fallen leaves to reduce fungal inoculum around the planting area. This does tend to be a chronic issue in cherry trees in this area, and it is typically worse in wet weather years.
Here is more about cherry shot hole and how to manage it. https://extension.umd.edu/hgic/topics/cherry-shot-hole-flowering-cherries
Marian
