If your snowball bush isn't blooming as profusely as you'd like, there are a few possibilities. First, only prune after it has bloomed, so you don't cut off buds. If you did a hard pruning one year, you may see fewer blooms the following year. Insufficient light is another reason why you may not be getting maximum blooms. Plant your bush in a spot where it will get adequate sunlight, and keep any trees or shrubs near your snowball bush pruned back so that it gets more light.