I pruned my peach tree and discovered it is literally covered in cankers. It was not the case last spring. Both small and big branches, even some twigs are affected. I pruned what I could, but if I prune every branch that is affected it would be probably bald trunk. I can’t also cut all of the cankers with knife, it is too many of them and tree is tall. Also I noticed, that 1/2-1’’ branches I pruned have their hardwood kind of dark. Does it mean I am loosing the tree? Does it make sense still keep it until it is gone on its own? Would it spread the canker on near by trees? I have young plum near by and I see one low branch on it has some sore as well - though it may be rabbit damage.
Are there any system treatments to the canker other them surgical removal? Any preventive techniques?
Galina,
Canker often occurs because a tree is stressed. As long as it is not caused by insect damage like borers, I use a " wait and see" method.
This past two months we have had wacky weather that has put a lot of stress on our trees. That could be one reason while you see oozinf everywhere. NHealthy trees can withstand canker and heal itself.
Also, with a few trees I have, I am not rushing to prune my peach trees.
Thanks! Do you ever get borers? I need to spray copper while it is still dormant to fix curly leaf issue I got last year, and I want to prune it before it, this is why I am doing it now.
Yes. We have borers, the peach borer kind, not the twig borer one( that is more of a West Coast issue).
Are your peach buds totally dormant. Copper of peach leavecurl is effective if sprayed when buds are dormant. Spray for PLC in late fall would work, too.
My peach buds start to push. Will will spray copper for other thing like bacterial spot ( yes, we have that, too), not for PLC as it is quite late now.
Hmm… I fall I’ve been told wait for spring to spray for PLC 
. The leaves buds still looks dormant as far as I can tell…
It is all about timing, either spring or fall… Spring spray for copper for PLC is fine as long as buds are dormant.
My peach buds stared to move now. If your buds have not pushed, you will be fine to spray.
My peach has natural “refrigerator” around it. It is on the north side of the house and near driveway, so all the snow from driveway ends up around it, and not in hurry to melt. I actually used the pile today to get to the upper branches to prune.