Belle grows well in the north but your tree doesn't look like Belle. I have belle of Georgia and mine are round on botton and Belle peaches stay light yellow color while your peach already has red color. Your HD tree has probably been mislabeled. When does your peach ripen? Does it taste like a peach. What color flesh yellow or white. Thinning lets the peaches grow to a large size. Too many peaches break branches. Peaches on thin branches snap later. Too many fruit stresses the tree so it gets sick.

The leaves look pretty good to me.I have a Nectarine whose foliage doesn't seem quite as nice as that. The size is your choice.I'd probably not take a lot off.It needs to fill out some.There are some decent pruning videos on the Dave Wilson Nursery site.Check out the Summer ones for now.Brady

Laurie: Agree with Olpea that your peach tree is suffering from bacterial canker. No need for me to take an entire page to explain what it is; Google it yourself and read all about it. Bacterial canker is common on peach trees, and has nothing to do with borers. I dormant spray peaches with copper each season to try to prevent this disease from getting a foothold on my stone fruit trees. A tree with canker at that point on the trunk is a goner, since you can't really prune it off without destroying the tree. I can't get to your photos of the leaves, but if they are dead then so is the tree, regardless of your experience with some other tree that you do not specify. A spring freeze may temporarily cause damage to emerging leaves, but on a healthy tree they quickly recover. So that's not it either. Peach leaf curl is common in climates that have consistently cool, moist spring weather and a slow warmup, but curl must be a relatively rare occurrence in Colorado. Don Yellman, Great Falls, VA

Depends upon how much you removed when you pruned. Peaches bear fruit on wood that grew last year.