A variety of problems can affect your trees over winter, and you may not even realize that the plants are suffering until new growth begins to show in mid to late spring. Fortunately, many winter problems can be remedied if you know how to properly deal with the damages.
Sunscald occurs when the winter sun heats up a tree trunk sufficiently for the sap to begin to flow, but then temperatures plummet below freezing again. The sap freezes and expands, splitting the bark. As long as the damage doesn't completely surround the trunk, the tree should heal. If the damage completely surrounds the trunk, then the tree is girdled and won't be able to transport nutrients -- removal of the tree is typically the only option. You can't do much about this problem in the spring, but wrap the trunk next fall so that further scald doesn't occur.
Evergreen trees suffer from desiccation when winter winds suck the moisture right out of the leaves or needles. This is especially common when the ground is frozen since the tree can't take in moisture to replace that which evaporates due to wind. Begin irrigating the tree every 7 to 14 days as soon as the soil begins to warm. Prune out any dead, brown branches that haven't recovered by early summer.
Ice damage and snow damage are more common on evergreens, but they can also affect some deciduous trees. Most of the damage is due to the weight of the ice causing branches to bend and break or the canopy to split open. Broken and cracked branches must be properly pruned out. If the canopy has split, you may need to have branches tied and supported so that they can strengthen and begin growing in the right form again.
Most trees produce new growth at the branch tips. This tender new growth typically begins to emerge in late winter and spring. A late-season freeze can sometimes kill back these tips, causing the new buds to drop off or to rot on the tree. The bad news is tip die-off can lead to fewer leaves and flowers on your tree. The good news is that you can simply trim back the dead tips and the tree should survive.
Road Salt Issues
Trees that grow near a road or sidewalk can suffer from salt overload if you or the city uses road salt on ice. Trees that are affected may produce yellowish foliage or leaf out weakly. You can prevent salt damage by watering deeply as soon as the soil begins to thaw out. The extra water will flush excess salts from the soil.
Work with a tree service in your area for more help.