Q.How And When To Prune A Blind Espalier Apple Tree Of About 10 Years Old
I don’t think that I pruned it hard enough last winter. I tend to prune in the Summer but the shoots are now about 12 inches long and if I cut back to about four nodes there would be no leaves left!
Certified GKH Gardening Expert
I don't see a reason to prune, at this time, unless you want to shorten the primary branches.
Here are some articles that will help you to know when and how to do this: