Dogwood trees are understory trees that prefer shade to full sun. They grow crooked, winding branches and produce delicate white or pink flowers in the spring. If a branch becomes weak or dies, it might break off or need to be trimmed to keep disease from attacking. Once a part of the tree is exposed to the elements, it is best to patch it to further prevent disease from developing in the wound and spreading throughout the tree.
Cut around the wound with a knife if it was caused by disease or mold. If it is simply a cut branch end from your pruning, there is no need to remove any extra wood.
Cut off splinters from branches that have broken off from storms or decay.
Clean a diseased or damaged wound with alcohol using a rag. This will kill mold and sterilize the opening.
Paint the wound area with a tree paint to protect the area from disease. Check back often to look for cracks in the paint. If there are, then repaint. If the wound decays some after painting, then you will need to cut out a larger area, clean and repaint.