Asked on Feb 19, 2020

How can I change the colors of hydrangea flowers?

Betsy Baum
by Betsy Baum

I’ve heard that you can change the colors of hydrangeas by using baking soda. Do you know about this?


  10 answers
  • Gk Gk on Feb 19, 2020

    If you can lower or raise the acidity of your soil by adding things to your soil you can try to change the color of your hydrangeas. Here's some info for you!

    https://www.gardenista.com/posts/magic-trick-how-to-make-your-hydrangea-change-color

  • Mogie Mogie on Feb 19, 2020

    1. Make Sure You Have the Right Type of Hydrangea — Only hydrangea macrophylla (aka mopheads and lacecaps) can actually change color, so make sure you buy the right kind.
    2. Measure the Soil pH — It's easy — we promise! Use a soil test kit to figure out your soil pH levels. To get blue flowers, you'll want your soil to be acidic with pH levels of 5.5 or lower. For pink flowers, you'll want more alkaline soil with pH levels of 6.5 or higher. To achieve that pretty palette of blue, pink, and purple hues, get your soil to a pH level between 5.5 and 6.5.
    3. Adjust the pH Levels of Your Soil to Get the Color You Want — Bailey's Color Me Blue (soil sulfur) or Bailey's Color Me Pink (garden lime) are great for adjusting pH levels, but you can also use a few homemade tricks, like using composted oak leaves, pine needles, or coffee grounds for blue flowers or wood ashes, lime, or fertilizers with high levels of phosphorus (a ratio of 25-10-10 is best) to prevent aluminum from entering the plant's system for pink flowers. This helpful guide will tell you how much additives to use for raising or lowering the pH levels.
    4. Keep Treating Your Soil, and Be Patient — Continue treating the top layer of soil around the root area to keep the flowers in the desired shade. This process can take months, so be patient.


  • Kathy Gunter Law Kathy Gunter Law on Feb 19, 2020

    It's the pH balance. Baking Soda and coffee grounds are two of the items that can effect the color of your flowers. The article posted by Gk is a really good one.

  • Linda Sikut Linda Sikut on Feb 19, 2020

    Hi Betsy,

    Here's another article to research how to have blue hydrangeas. Wishing you the best.

    https://www.popsugar.com/home/How-Change-Color-Hydrangeas-37062661

  • Vimarhonor Vimarhonor on Feb 19, 2020

    Hello! The pH of the soil that determines the flower color—specifically, whether or not the hydrangeas are taking up aluminum from the soil. If the flowers are pink, the plant is getting aluminum. If they’re blue, it isn’t.

    You can control the color by altering the pH.

    Soil testing can determine your pH.

    Acidic soil, with a pH lower than 6.0, yields bluish hydrangea blooms. Alkaline soil, with a pH above 7.0, promotes pinks and reds.

    pH between 6 and 7, the blooms turn purple or bluish-pink.

    To lower your soil pH, add garden sulfur or aluminum sulfate to your soil.

    To raise the soil pH, use ground lime.


    Hydrangeas are some of my favorite flowering shrubs—- best of luck with your gardening adventures!

  • Redcatcec Redcatcec on Feb 20, 2020

    Hi Betsy,


    Here is a very informative link for you on Hydrangeas and their colors:


    https://www.diynetwork.com/how-to/outdoors/gardening/hydrangea-colors



  • Chloe Crabtree Chloe Crabtree on Feb 21, 2020

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

  • Maura White Maura White on Feb 23, 2020

    You can change the pH of the soil. More acidic soils will be blue blooms - 6.5 or higher will give you pink blooms. If you add baking soda, you will make it more basic. If you want pink blossoms, then add it. Otherwise get an acidic fertilizer at a garden store for blue blooms.

  • Kmdreamer Kmdreamer on Feb 25, 2020

    Yes you put the baking soda around the base of the plant