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How To Keep Hydrangeas Pink

Hydrangeas are admired by everyone across the world for their colorful-ball-like flowers. Some prefer blue hydrangeas, some love pink hydrangeas, while others find purple more royal and rare.

How to Keep Hydrangeas Pink

Which One Do You Prefer?

If you love pretty pink and want your hydrangea blooming big-showy pink flowers, this article is for you. In this brief guide, we will let you know all about the mechanism of color variation in Hydrangeas.

What are the most effective ways to change the color of your hydrangeas to pink? What role pH and aluminum content play in determining the color of hydrangeas?

To know how you can grow pink hydrangeas, let’s first understand the mechanism of color variation in hydrangeas.

What Is The Mechanism Of Color Variation In Hydrangeas?

According to studies, the color variation in hydrangeas depends on the soil’s aluminum content and pH level.

The high content of aluminum grows beautiful blue hydrangeas. In contrast, low or no content of aluminum grows pretty pink hydrangeas.

If aluminum determines whether the hydrangea will bloom blue or pink flowers, how does pH affect the color variation? The aluminum content in the soil is indirectly linked with the pH level of your garden soil. If your garden soil has a lower pH level, it is more likely to have a higher aluminum content.

A higher pH level may signal that your garden soil has a lower amount of aluminum. Thus, it is highly significant to determine what is the pH level of your soil before deciding the method.

How To Check The Soil Ph Level?

  • The simplest way to determine the exact pH level of your soil is through lab tests. Bring a little amount of your garden soil to the nearest nursery or any local extension service. The local extension service will run the test and let you know the exact pH level of your garden soil.
  • Another simple and quick way to check the pH level of your garden soil is through the soil test kit. If your soil pH level is below 5.5, then it is acidic. If the pH level is at or above 7, then your soil is alkaline and perfect for growing pink hydrangeas.

Once you have determined the pH level of your garden soil, now let us help you modify the pH level of your garden soil.

The perfect pH level for growing pink hydrangeas is around 6.5 to 7.5. Keep in mind that more than this may harm the nutrients balance of the soil. Following are the most effective ways to maintain soil alkalinity and grow pink hydrangeas.

Ways To Keep Hydrangeas Pink

Garden Lime

To alter the pH level of your garden soil and grow pink hydrangeas, use garden lime. Generally speaking, people use garden lime to make the soil neutral or more alkaline where the soil is highly acidic.

Garden lime, also known as calcium carbonate, provides the soil with the right amount of calcium. Calcium is a healthy nutrient required for proper hydrangeas growth.

For pink hydrangeas, dip garden lime deep into your garden soil. For better results and high soil alkalinity, the garden lime should be well incorporated into the soil. The garden lime doesn’t dissolve well with the water and needs more soil moisture to show better results.

Keeping Hydrangeas Pink

How Much Garden Lime Should You Add To Increase The Soil Ph?

How much garden lime you should add to the soil for pink hydrangeas primarily depends on the two main factors

  • What is the pH level of your garden soil?
  • What is your garden soil texture? Is it clay soil or sandy soil?

The below table will help you choose the right amount of garden lime.

Soil TextureSoil pH Between


Soil pH Between


Soil pH Between



400 g/m²

250 g/m²

150 g/m²


550 g/m²

325 g/m²

200 g/m²

Clay sand

950 g/m²

625 g/m²

350 g/m²

Though the results of garden lime last for a long time, it, unfortunately, takes a long time to kick in. You have to add garden lime repeatedly in the fall to see satisfactory results in the spring.

How To Keep Hydrangeas Pink Naturally?

Baking Soda

Baking soda is the most cost-effective way to turn your hydrangea flowers to pretty pink. Although it is the most inexpensive way, the results don’t last for a long time.

You have to add baking soda, again and again, to maintain the soil alkalinity for growing pink hydrangeas. The best practice is to check the soil pH level after every two to four weeks.

Other than being inexpensive, baking soda is also very gentle on the plants. Therefore, you can use baking soda on hydrangeas without any worry.

As baking soda is very alkaline with a pH level of 8, a little amount is enough to increase the soil alkalinity to grow pink hydrangeas. Be careful and add only a tablespoon or 10 grams per one gallon of water.

Too much baking soda can make the soil more alkaline and disturb the natural ecology of the soil.

Animal Manure

According to a Journal published by the Soil Science Society of America, animal manure can effectively increase the soil’s pH level. To grow pink hydrangeas, cover your garden soil with fresh cattle manure.

This will not only increase the soil alkalinity to grow pink hydrangeas but will also increase the number of nutrients in the soil.


To grow big showy flowers of pink hydrangeas, choose any of the above methods. The higher pH level of the soil will directly affect the number of aluminum in your garden soil.

The lesser amount of aluminum will let your hydrangea bloom pretty pink flowers. The higher the soil alkalinity, the pinkier will be the blooming flowers of the hydrangeas.