Karen Ackley, Ag and Horticulture Assistant at the Iowa State Extension Office in Marion County, says this winter has been very hard on trees. She says they are much like humans in that if there is any vulnerability, stress will bring out that vulnerability and will have a damaging effect on it. Other tree damage that can occur over winter happens if the the tree is struck by a snow plow, or if the bark is eaten away by rabbits. She says trees generally do not recover from this kind of damage. She adds that once the tree is adversely affected, that is when insect infestation is more likely, as well. Ackley says at this point keeping the tree watered and mulched is the best thing to do – she advises against using fertilizer, which could cause more damage.