As the name suggests, Incrediball Storm Proof smooth hydrangea ( Hydrangea arborescens ) tackles the most common complaint people have with the genus: while other smooth hydrangeas flop, this incredibly stout and sturdy stemmed beauty holds its blooms upright during—and even after—heavy summer downpours. Though its blooms aren’t quite as gigantic as the original Incrediball®, they are so numerous and large in proportion to this compact variety that it absolutely lives up to the expectations associated with this now household name. It's a robust, vigorous, heavy bloomer with a rounder, denser habit than other smooth hydrangeas.