What is causing reddish brown spots that turn to holes on my new Yoshino cherry trees?
I planted two young Yoshino cherry trees, and they have started getting spots on them that gradually fall and make holes. New leaves continue to grow, but many on the entire tree look like they are shredded because it is taking over entire leaves. What can I do or use to stop this? I don't want the trees to die.
This appears to be a disease called shot hole. After the tree goes dormant this winter prune out infected tissue (twig cankers). It’s a little late to treat for leaf spot. To control leaf spot, spray when the tree is blooming next spring. A liquid copper fungicide will probably be effective against both the bacterial and fungal versions of the disease- something like Natural Guard Copper Soap. You can try spraying a fungicide containing the active ingredient chlorothalonil (Bonide Fungonil is an example, but there are MANY brands).