ShotHoles diseases on leaves of plum Trees

[Lovetoplant]

Hello,  the leaves on my plum trees have bacterial disease call shothole disease.  Does anyone know how to rid of it?  I have been spraying the trees with Liquid Cop(liquid copper) since December last year once every 10 days or so up until now.  All new leaves are starting to show this symptom again.

[Daintree]

Copper sprays can actually damage the leaves, and usually trees are just treated in the fall, after leaf drop. You can treat again in the spring, but every ten days for three or four months seems excessive. Spraying dormant twigs and buds should have prevented carryover to new growth, so I am wondering if you are just overapplying. expect it to take a couple years to get it under control.

Carolyn