Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but.
Sep 21, Cut back all branches to within a foot of ground level. Although you will sacrifice blooms for that year, a healthier, happier snowball bush should emerge the following season.
If you cannot bear to part with all the blooms for the entire season, consider splitting the renewal pruning over three years, removing one-third of the old canes each year. If you choose to prune this bush, do it after the flowers fall off in early summer.
Can you keep a snowball bush small? A: The best time to prune a snowball bush, Viburnum macrocephalum, is after it finishes blooming and the white flowers have turned brown. Keep in mind that this shrub is. The best time to prune your Viburnum snowball bush is after the flowers bloom in spring, since you can destroy next year's flowers if you prune it too early or late.
You are currently in Growing Zone Planting Elsewhere?
Use a clean, sharp pair of shears to cut the oldest, thickest shoots as near to the ground as you can to get rid of them. If your Snowball is already mature, you can grow more bushes using cuttings from a healthy plant. Test branches to see if the wood is soft. If the branch bends before breaking in two, it can be cut off using sharp pruning shears and planted stem-down to grow new bushes. When to Plant Your Snowball Bush.