Hydrangea serrata Tuff Stuff Ah-Ha is a sturdy, 2-3 foot tall and wide, reblooming mountain hydrangea with beautiful double florets of sky blue in acidic soils, lavender and lavender pink in neutral soil, and light pink in alkaline soil. Blooms emerge on old wood in early summer and then on new wood from mid summer through autumn. Mountain hydrangea tend to be smaller than and perform better in zones 5 and 6 than Hydrangea macrophylla.
Asia and the Pacific - Asia - China and Japan
Woodlands to 1500 m in the mountains of central and southern Japan.