Ia kousa dog wood which flowered beautifully this year but has gotten too large.
Dear Gardener: Pruning immediately after bloom helps as the tree will not have formed the next years flowers. However, care must be taken that you are not simply removing all the growing tips on the top of the tree and leaving stubs. Try reducing the height of the tree by cutting back 1/3 of the tallest branches each year for three years. This way you will save the growing and flowering branches and in three years have a lower tree. Maybe a good tree person would be helpful.