When the freeze threat dwindles and trees and shrubs begin to bud, is the time to prune unsightly frost damage. Though it's tempting to trim limbs right after a killing chill, waiting is worthwhile. Damage may be only superficial and, come spring, affected branches may leaf out again in full or in part. If that doesn't happen, prune back any damage with an eye toward maintaining an attractive shape. Use sharp loppers to make clean cuts. Follow with water and fertilizer to spur new growth. And once frosty nights are history, don't forget to move plants you've sheltered back to spots where they can enjoy the warm spring sunshine.