The top of my river birch tree snapped during a storm. I cut the remains at a 45-degree angle. It is about 6 inches in diameter. Should I put a special dressing on it?
It is usually better to let it heal itself. Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/trees/tgen/what-to-do-for-storm-damage-trees-repair.htm