should instead consider the Chinese snowball (Viburnum macrocephalum) which is strong in zones 6 through 9. One somewhat confusing species of this undeniably beautiful plant is Viburnum opulus.
Usually, however, "snowball" refers to either Viburnum opulus 'Roseum' or Viburnum macrocephalum. The latter is often called Chinese snowball viburnum, while the former goes by several names ...