The Science Behind Hydrangea Colors

No, baking soda does not make hydrangeas pink. The color of hydrangeas depends on the ph level of the soil they are planted in.

If the soil is acidic, the flowers will be blue, and if it’s alkaline, the flowers will be pink or red. Baking soda, which is a base, can slightly increase the ph level of the soil, but it’s not enough to make a substantial difference in the color of the flowers. Other methods, such as adding aluminum sulfate or lime to the soil, can help adjust the ph level and change the color of the flowers. Understanding the science behind hydrangea flower color can help gardeners achieve the desired hue for their plants. In this article, we will explore how hydrangeas get their colors and discuss some techniques for altering them.

The Science Behind Hydrangea Colors



Hydrangeas are known for their ability to display a wide range of colors, including white, blue, pink, purple, and red. The color of hydrangeas is determined by the soil ph. Typically, hydrangeas grown in acidic soils will produce blue and purple blooms, while those grown in alkaline soils will produce pink and red blooms.

The reason behind this is that the soil ph affects the availability of naturally occurring aluminum in the soil. When the soil ph is low, aluminum is easily available, which causes the flowers to turn blue. When the ph is high, aluminum is less available, allowing the flowers to turn pink.

Baking soda can be used to raise the soil ph, thus making the hydrangeas produce pink blooms. However, the amount of baking soda used should be carefully monitored as too much can harm the plant.

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Understanding Soil Ph And Hydrangea Colors

Soil ph plays a significant role in determining the color of hydrangeas. Low ph level produces blue hues while high ph level results in pink or even purple. The ph environment dictates how hydrangeas absorb available aluminum and iron from soils.

Therefore, if soil already contains a sufficient quantity of aluminum and ph is acidic, then it will lead to blue hydrangeas. Alternatively, when the ph is more basic, it enables hydrangeas to absorb more aluminum, resulting in pink hydrangeas. Hence, identifying the ph levels that produce specific hydrangea colors are crucial.

A ph test meter or kit is a great tool for determining the acidity level in your soil. Knowing your soil ph can help you to grow beautiful, vibrant, and healthy hydrangeas.

How Do Hydrangeas Change Colors?

The Role Of Baking Soda In Changing Hydrangea Colors

Baking soda can play a role in changing hydrangea colors by influencing the soil ph. The hydrangea’s color is determined by the acidity level of the soil, with more acidity encouraging blue flowers and less acidity producing pink ones. Adding baking soda to the soil can raise the ph and reduce soil acidity, making the hydrangea flowers turn pink.

However, this doesn’t always work, and it depends on the hydrangea variety and the current ph level of the soil. Experimentation is key, and it’s important to avoid adding too much baking soda, which can harm the plant. Overall, baking soda may be able to help produce pink hydrangeas, but it’s not a guaranteed solution.

So, it is important to do more research and try out different formula to produce pink hydrangeas.

Factors Affecting The Success Of Baking Soda Treatment

Changing the color of hydrangeas can be achieved through a simple baking soda solution, but the outcome depends on several factors that can impact its effectiveness. Soil type, sun exposure, and water quality can all play a role in determining whether the hydrangeas will turn pink or remain blue.

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It’s important to identify these environmental factors before applying the baking soda solution. Best practices for using baking soda to change hydrangea colors include testing the soil ph, applying the solution during the appropriate time of year, and watering the hydrangeas thoroughly.

With proper preparation and application, baking soda can effectively alter the color of hydrangeas to a beautiful shade of pink.


Baking soda treatment may affect hydrangea color, but it’s not guaranteed. Results may vary due to soil acidity. It’s important to test ph and adjust before applying the treatment. Overuse of baking soda can damage the plant. If you choose to try the baking soda method, consider applying it before the blooming stage.

Additionally, there are other ways to alter hydrangea color, such as using fertilizers or aluminum sulfate. It’s important to research and consult with a gardening expert before attempting any treatments. Remember to always follow instructions carefully to avoid harming your plants.


There are a lot of myths surrounding hydrangea color changes, and scientists have been hard at work testing them. So, will baking soda make hydrangeas pink? The evidence is inconclusive. While some people swear by it, others have found no difference in their flowers’ colors.

One thing that is clear is that ph levels can affect the color of hydrangeas. Altering soil ph can change the availability of metal ions and impact the plant’s ability to produce pigments. Other factors such as the type of hydrangea, sun exposure, and watering can also have an impact on the flowers’ color.

Ultimately, it may take some trial and error to figure out what works for your specific plants. But whether you end up with pink or blue blooms, there’s no denying the beauty and joy that comes from growing hydrangeas.