Doubled showy florets, each shaped like a small waterlily, ring the lacecap flowers of this mountain hydrangea in pink or blue. Hydrangea serrata Tuff Stuff Ah-Ha® 'SMNHSDD' grows 2 to 3 feet tall and wide in part sun to part shade, hardy from Zone 5 through Zone 9.
The doubled florets give each flower head a fuller look than a single lacecap while keeping the open center of fertile flowers. It reblooms, flowering on old and new wood.
Mountain hydrangeas change color with soil pH the same way bigleaf hydrangeas do. Acidic soil below about 6.0 gives blue, alkaline above 7.0 gives pink, and the range between produces purple or a mix of pink and blue on the same plant. Aluminum sulfate pushes flowers toward blue and garden lime pushes them toward pink, and either takes a season to show.
Hydrangea serrata is a close relative of bigleaf hydrangea, with smaller leaves, finer stems, and flower buds that hold up to cold much better. Buds formed on old wood in late summer come through hard winters and late spring frosts that often cost a bigleaf hydrangea its bloom, and that bud hardiness is the main reason to choose a mountain hydrangea. Prune in summer after the first flowering and no later than August, since cutting in fall or early spring removes next year's buds. Dead stems can come out in spring, once new growth shows which ones are dead.
The size suits a foundation bed or a container.
Size at Maturity
Height 2'- 3' Spread 2'- 3'
Growing Zone
USDA Hardiness Zones 5-9
Lowest Temperatures -20°F to -10°F
Light Requirements
Part sun to part shade - 3 to 6 hours of direct sun, or dappled light through the day
Wildlife Benefits
Special Conditions
Reblooming
Seasons of Interest
How to Plant
Give your new plant the best start possible. Click here for general planting instructions.
Grow With Confidence
We stand behind every plant we ship. Click here to view our warranty.