summer pruning wont stimulate new growth, it is for shaping the tree.
On Sat, 14 Jul 2007 11:01:09 -0500, "cat daddy"
wrote:
"The foliage on the trees is so dense that we will have to do a lot of
summer pruning to allow adequate sunlight to enter the inside of the canopy
of the trees," Psencik says. "This can have a great effect on the amount of
next year's peach crop."

So, apparently pruning in Summer is not a bad thing.