How to Change the Color of Hydrangeas

A quick way to achieve a change in flower color is through liquid soil drenches.

To make the flowers BLUE or more blue:

Dissolve one tablespoon of Aluminum Sulfate in a gallon of water and drench the soil around the plant every 2 weeks in March, April and May.

To make the flowers Pink:

Dissolve one tablespoon of hydrated lime in a gallon of water and drench the soil around the plant every 2 weeks in March, April and May. Avoid getting the hydrated lime mixture on the foliage because leaf burn could occur.