Changing Hydrangea Color: The Choice is Yours

Written by admin on May 29, 2017. Posted in blog, Flowers, Hydrangea

How to change the color of your Hydrangea plant

There is nothing like walking into a Hydrangea garden and seeing a beautiful palette of blues, pinks and purples. Here on the farm we use hydrangeas throughout the season for arrangements, centerpieces and to adorn our home. Our main stock were the parent plants that were placed back in the 1950s when the house was built. They were massive 8 ft high plants, that we propagated heavily, and then had to remove because they just couldn’t thrive in our hot California summers.

The only problem? They were all pink!! (Some of you are saying, “What’s the problem?”) We wanted to create a variety of bloom colors for our Hydrangea loving customers, and to grab attention at the farmers market. Well, it worked. How did we do it?

So, unlike most flowers, the lacecap and mophead hydrangeas can changes colors. Fortunately for us, it is as easy as changing the soil pH. Hydrangeas are the litmus test in the flower world. Below are the pH ranges, and resulting colors:

Generally speaking for hydrangeas, acidic soil, with a pH lower than 6.0, yields blue or lavender-blue hydrangea blooms. With alkaline soil, with a pH above 7.0, promotes pink and red hydrangea blooms. With a pH between 6 and 7, the flower blooms turn purple or bluish-pink. To lower your pH, add a garden sulfur or aluminum sulfate amendment to your soil.

Use a pH Meter to Manage Hydrangea Color

How can you change the pH? You can get a pH soil test kit to be exact, but that is not me 😉 I just used a pH soil and moisture meter to test. I had pink, and wanted blue, so I wanted to lower the pH to create a more acidic environment. To do this, I added aluminum sulfate (you could also use garden sulfur). I sprinkled it around my hydrangea beauties, scratched it into the soil, and waited for a big rain. To raise pH, you can use ground lime. Use the same technique. Good luck on changing your Hydrangea color!