ok, before this thread goes south on squirrels.....this is what t-bone said......
"I would shoot them, but right now I don't own a rifle and besides, I can't be there all day to guard the trees."
i don't have any suggestions t bone, i don't have peach trees.
edit and add: t bone, not sure how tall your tree is or how big the base of it is, you might try stove pipe around it, i use several sections around an 8 x 8 post for my bird feeder, the surface is too smooth for them to climb, and they can't jump high enough to get past it.