Watch the foliage for further color changes and the twigs for brittleness. Many of the buds may have survived; if the twigs are still pliable then the shrub is still alive. Do not fertilize at this time, this could stress the shrubs further.  Wait until new growth emerges in before pruning out injured foliage. Winter burned foliage is most likely dead and will not green up, but the buds, which are more cold hardy than foliage, will often grow and fill in areas where brown foliage was removed.Be sure to water trees to avoid drought-like conditions throughout the spring, summer, and fall if we are not getting a lot of snow and rain in order to minimize additional stress.