I have a Japanese Pagoda Tree that apparently was damaged by a late freeze. It had started to leaf out in March then all of the leaflets turned brown after a freeze. We have been watering it, and the wood was green, though now there are less green twigs and branches and more brown. The trunk and major branches still appear to be green. I don't see any signs of re-leafing. Should I prune this tree back to try to force growth ? Or is it hopeless and it needs to be replaced ? Thanks.