Heavy snow can be damaging to trees, even dormant deciduous trees. If a branch is weak or the load is heavy, it may give way and break. The following guide can help you determine what to do if a branch breaks off of a dormant tree, along with providing some ongoing care advice to prevent future breakage.
Consider a splint
When surveying the break, determine whether the branch is worth saving. A split or slight break may be salvageable if the main body of the branch is still attached to trunk. In fact, it may be the only way to save the tree if it needs the branch to remain healthy or balanced. In this case, carefully move it back into position and wrap gauze or burlap around the split branch and the trunk so that the branch is held back in place. You can remove the splint after a year, or you can opt to bolt the branch back in place instead of splinting. Keep in mind, trees don't heal like animals do. New bark will grow over the split and fuse it back together, but the break will remain internally so the spot may be weaker even after it looks healed.
Remove it cleanly
If the damage is complete or if the branch doesn't need to be saved, pull out the pruning saw and cut it off. You want to cut right in front of the raised bark at the base, which is known as the branch collar. Even if the branch broke off completely on its own, use your saw to clean up the rough edges of the break. With a clean cut, the branch collar will put on renewed growth in the spring, allowing it to form a callous over the wound so that insect and disease organisms can't invade the tree.
Prevent future breaks
Going forward, the best option is to prevent breaks from happening in the first place. The easiest way to do this is when you trim the tree. Any branches that emerge from the trunk at a less than 45 degree angle or greater than 90 degree angle are more likely to break or split under heavy snow. These should be trimmed out so the remaining branches that are at a healthy angle remain. This will also open up the canopy so it has better air circulation and doesn't catch as much snow.
For more help, contact a tree care and removal service in your area.