Shade hydrangeas prefer moist soil and regular watering during the growing season. For most, in order to obtain the blue flower color, apply 2 tablespoons of aluminum sulfate near the base of the plant. A rusty nail or coffee grounds will also increase the acidity of the soil which makes the flowers turn blue.
Tuff Stuff™ Ah-Ha Hydrangea
Hydrangea serrata 'SMNHSDD' USPP 29,832; CBRAF
Like the other Tuff Stuff™ hydrangeas, these guys pack a punch with a small body! Manage your soil pH to manipulate the blooming colors from pink to purple to blue and back as you wish when you plant or over the years. Tuff Stuff™ reaches a mature height of 2 to 3 feet and a mature width of 2 to 4 feet. This repeat bloomer is great for borders, container, mass planting, edging, focal, specimen, water garden, accent, and cut flowers.