The silverback hydrangea occurs most frequently at the southern end of the Blue Ridge Mountains above 2,800 feet, notably in western North Carolina. Given the sloping nature of its natural habitat, it succeeds best as a garden variety in sharply drained soil that is amply watered. The truth is we have trouble growing this plant in the garden here (1,000 feet elevation, outside Atlanta). We often wonder why we offer it. We are asking for trouble. Yet, it is so lovely. Our two specimens planted in the garden here are very happy 4-5 foot plants. The flower is white & mostly fertile with just an occasional showy sepal supported by the glorious silver underside. 3+ feet tall. Zones 5-7(a).