Although they look similar, snowball bush (Viburnum plicatum) and the snowball hydrangea (Hydrangea arborescens) are actually two different plants.
The two are both deciduous shrubs with similar characteristics and some distinctions.
Snowball bush, also called Japanese snowball bush, is a native of China and Japan and grows in USDA plant hardiness zones 5 through 8. Snowball hydrangea, also called smooth hydrangea, is native to the Eastern United States and grows in USDA zones 3 through 9.