Snowball bushes require pruning throughout the blooming season to remove old blooms. This will encourage good health and new bloom growth.
The snowball bush is really a form of big leaf hydrangea called a mophead hydrangea. Like all hydrangeas, mopheads need pruning to remove dead flowers. This should be done throughout the blooming season and will stimulate new growth. Broken, dead or shriveled stems can also be removed; however, do not remove woody, but otherwise healthy stems. These are second year growth and usually produce the best blooms. Pruning can also be done in early spring to help the bush maintain a round shape.