Late bud break
The cold, dry weather this last winter has contributed to a number of issues this spring. While insect populations may be down, tree stress is up and that might spell trouble later on. One reason could be that the ground froze to a much greater depth than usual, damaging sensitive roots. The damage has slowed bud break this spring in individual maple, ash, honey locust and elm. Some trees still have not produced any leaves, although the buds and bark appear healthy. Those that have leaves, but produced them late, appear thin with undersized leaves. That is good indication of stress and potential for decline.
While patience is the best bet for right now, later on it will be important to watch for signs of secondary pests. Stressed trees are more susceptible to borers and root disease both of which can eventually kill the tree. Minimize new stresses and wounds, water during dry spells and regularly inspect ailing trees. Then cross your figures. If the trees were fairly vigorous prior to injury, they will likely recover, although this year they may not look like much.