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.
Endless Summer® Hydrangea
HYDRANGEA MACROPHYLLA 'BAILMER' PP15,298
Endless Summer is the original re blooming Hydrangea that blooms on old and new wood. It's flower color can be blue in very acidic soil while pink in alkaline soil. In the old days, iron nails would turn a hydrangea blue but since most nails are now steel, it's best to use aluminum sulfate to turn your hydrangeas blue.