Two hydrangea species are considered native for U.S. East Coast and suitable for U.S.D.A Hardiness Zones 5-7. They are: H. quercifolia (oakleaf hydrangea) and, H. arborescens (smooth or wild hydrangea ...

which varies between hydrangea species and varieties. If the USDA zone of your location matches the hardiness zone requirements of the hydrangea you planted—and the rest of the growing ...