I had fire blight on a couple of young apple trees last year, I tried to cut some of the affected wood out, but I couldn't cut all of it out without cutting most of the tree out. I just sprayed with copper and dormant oil this week.

Should I spray with copper again this winter/spring? I'm unclear on how often and at what stage copper can be sprayed for blight on apples besides the dormant spraying that I just did.

Thanks.