I hope your tree is fine, Karen. I would think if it where sunburn. The leaves would be showing it on all leaves or at least on side of tree, not just the apex of each branch.
I think Kadie has the right direction to follow.
Karen, when you say you water, but no water comes out of the bottom. It is best to water enough so that water or water/fertilizer mix always flushes through and out the bottom.
This will flush out any unused or build up of salts. This may be different if dealing with dormant trees for watering.
Definitely worth a lifting.
Rick
