How do I get Endless Summer , All Summer Beauty, and Light O Day Hydrangeas to change bloom color from pink to blue?
Soil pH affects the flower color (blue in highly acidic soils and lilac to pink in slightly acidic to alkaline soils). Add aluminum sulfate to the soil to make the flowers blue or add lime to the soil to make the flowers pinker. Begin soil treatments well in advance of flowering, as in late autumn or early spring.
