How Long Does it Take For Hydrangea Blooms to Change Colors?

Are your hydrangea flowers the wrong color? This can be so disappointing. Luckily it is a simple process to change the color of your hydrangea flowers, but how long will this take? Will the blossoms change color in this growing season or will it take years and years? In this article, hydrangea enthusiast Jill Drago will go over how long this process will take and how to do it correctly.

Several slightly domed clusters of Hydrangea flowers bloom in a vibrant array of colors. The delicate petals showcase shades of pink, blue, purple, and yellow, creating a captivating spectacle. Intermingled among the blossoms, glimpses of lush green leaves add a refreshing touch of verdant beauty.


Hydrangea flowers are the perfect summer choice to fill your garden with bold textures and dreamy colors. Sometimes, the blues and pinks we dream of do not come to fruition in our gardens. This is simply because of the pH of our garden soils. This can be frustrating, but it is fixable.

Lucky for us gardeners, changing the color of your hydrangea flowers is pretty simple. The question is how to do so properly, and how long will it take for us to see our desired dreamy results?  

If you are ready to change the color of your hydrangea blossoms, continue reading. We will discuss how long this process will take and give some simple instructions on how to change the color of your flowers

The Short Answer

Changing the color of your hydrangea blossoms is not a quick fix. It can take months for the pH of your soil to change to the appropriate levels. You may notice the color changing slowly over time, but you will likely not see the full effects for a full growing season.

The Long Answer

A close-up of a Hydrangea plant reveals numerous blossoms with enchanting hues of pink and purple. The vibrant flowers stand out against a backdrop of meticulously trimmed green grass, creating a striking contrast. The presence of verdant green leaves further enhances the overall allure of the scene.
The larger the shrub, the longer it will take for the complete color change to occur.

Hydrangea serrata (mountain hydrangeas) and Hydrangea macrophylla (bigleaf hydrangeas) are the two types of hydrangeas that are particularly sensitive to the pH level of soil and can change bloom color. Panicle, oakleaf, and smooth hydrangea flowers cannot change color.

Getting that ideal shade of blue or pink can take several weeks, months, or even years. It depends on the soil’s existing composition and how often it is amended. Most soil pH amendment products should be applied every 2-3 months until the necessary pH level is established. Practice patience here!

For example, if the existing soil is alkaline but you are looking for a blue hue (which requires more acidity), it will take longer for the soil to reach the right pH level to achieve the desired color. This can take up to a few years in some cases.

However, if the soil is already slightly acidic, it wouldn’t need to be amended as much or as often. This means it would be a faster process, even as little as a few weeks.

With that in mind, it is quicker and easier to change your blue hydrangeas to pink rather than pink to blue. A healthy plant will also change faster than an unhealthy one. Another thing to consider is the larger your shrub, the longer it will take for the full-color change to take effect.

How Do I Get Started?

Changing the color of your hydrangea blooms only requires amending the soil’s pH level. However, you need to know a couple of things before you begin this process: the type of hydrangea you are growing and the pH of your soil. Once you have this information, you can get started!

Know Your Hydrangea Species

A close-up captures the intricate details of a slightly domed cluster of hydrangea flowers. At the center, green-yellow flowers are just beginning to bloom, radiating a sense of anticipation. The outer petals boast a delicate shade of pink, forming a harmonious blend of colors. As the background softly blurs, the focus remains on the lush green leaves that frame the blooms.
White flowering bigleaf hydrangeas will always maintain their white hue regardless of soil conditions.

As mentioned above, not every hydrangea can change the color of its blossoms. This neat trick belongs solely to bigleaf hydrangeas (Hydrangea macrophylla) and mountain hydrangeas (Hydrangea serrata). 

This is easy to determine if you have just purchased your hydrangeas and you still have the plant tag on hand. If not, you will need to do a bit of homework. Take note of when your hydrangea blossoms, what shape the flowers are, and if the flowers appear on older woody growth or newer green growth. 

If you know you are growing a bigleaf hydrangea, there is one more hitch. White flowering bigleaf hydrangeas are not sensitive to the pH of your soil. They will remain white no matter what you do to your soil. If you dream of pink, purple, or blue flowers, you will want to ensure you have the correct species and variety of hydrangea. 

A Few Hydrangeas That Can Change Color:
  • Hydrangea macrophyllaEarly Blue
  • Hydrangea macrophyllaNikko Blue
  • Hydrangea macrophylla ‘PIIHM-II’ PP25,566, or BloomStruck® Hydrangea
  • Hydrangea macrophylla ‘PHIIM-I’ PP20176, or Twist-n-Shout® Hydrangea
  • Hydrangea serrata ‘MAKD’, or Tiny Tuff Stuff Hydrangea
  • Hydrangea serrata ‘Bluebird’
  • Hydrangea serrata ‘Diadem’

Test Your Soil

Resting on brown soil, a soil pH tester stands out. A sprouting leafy plant grows alongside it, symbolizing new life and growth. The simple yet meaningful arrangement conveys the significance of understanding and maintaining the optimal pH balance for healthy plant development.
Knowing the pH level of your soil is crucial for determining the color of your hydrangea blooms.

Equally as important as your hydrangea species is the pH of your soil. You can either run a full soil test and learn all about the nutrients in your soil as well as your pH, or you can purchase a pH kit at your local garden center. 

Neutral soil has a pH of 6.5-7.5. This means that your hydrangea will likely bloom in a shade of pinkish purple, which can be perfectly lovely.

If your soil is 5.5 or below, your soil will favor blue blossoms. If it is 6.5 or above, you will notice your hydrangeas have more pink or red flowers. Once you have this information about your soil, you can begin amending your soil to achieve your hydrangea flower goals. 

Changing Hydrangeas From Pink to Blue

A hand delicately holds blue fertilizers, poised to release them onto the rich brown soil below. Lush green leaves stand proudly beside the fertile ground, representing the promise of vibrant growth and nourishment. The image encapsulates the care and attention given to nurturing the plants for bountiful results.
Holly-tone acts as a basic fertilizer but can also help lower the pH of your soil.

Achieving the perfect blue flowers takes a bit of time and patience. Some theories claim that regular household items such as vinegar, coffee grounds, or pennies can turn your hydrangeas blue. These methods do not work.

The proper way to do this is to amend the soil with the right acidity. Once your hydrangeas are blue, a few simple steps exist to maintain this unique and vibrant color.

You can begin by fertilizing your hydrangeas with a fertilizer for acid-loving plants such as holly-tone. This fertilizer acts as a basic fertilizer but can also help you lower your soil’s pH. 

Next, you will want to grab aluminum sulfate or a soil acidifier from your local garden center. If you can find a soil acidifier, I would recommend that. It is easy to apply, less harsh, and safer for you and your plants. 

Add your soil acidifier to your hydrangeas in the spring, and repeat every 60 days throughout the growing season until you have reached your goal. If your plants are new, you will want to use 1 ¼ cups of soil acidified. You will use 2 ½ cups per plant if you have established hydrangeas. Sprinkle this evenly around the plant’s dripline, beginning at the center and working your way out to just beyond the farthest branch.  

Changing Hydrangeas from Blue to Pink

Grasped firmly in a hand, a mini metal shovel with a wooden handle showcases its utility in gardening. The shovel is filled with white garden lime, pouring onto the rich, dark soil below. The harmonious combination of materials symbolizes the essential elements needed to enhance the soil's fertility and create an ideal environment for plant growth.
The finer granules of garden lime break down more effectively, quickly changing your hydrangea blossoms to pink.

Turning your hydrangea blossoms pink or red is a much simpler process that typically has quicker results. You can also use this process to amplify the color of your pink hydrangea blossoms. 

The only thing you need for this process is some garden lime. Garden lime is easy to find at your garden center or hardware stores. Do not apply lawn lime because it will not break down as nicely as the finer granules of garden lime. 

Beginning in April, apply 2-4 tablespoons of garden lime around the drip line of your hydrangeas. The dripline begins at the center of the plant and ends at the farthest-reaching branches. Water your hydrangeas well after applying.

Apply the garden lime again in the fall. Repeat the process in the next growing season and as needed to maintain your desired results. Adding too much too soon can be risky for your hydrangea, so follow the directions on the container to avoid root burn or other problems.

How to Speed Things Up

Three potted hydrangeas grace the scene, each displaying exquisite pink and purple blooms. The contrast of the vivid flowers against the black pots creates a visually appealing composition. The plants rest on a surface made of wooden planks, adding a rustic touch and highlighting the beauty of nature in a harmonious blend of colors and textures.
The soil containment in a container allows for quicker color changes in hydrangeas.

There is one way you can ensure quicker results: Container planting

Hydrangeas make beautiful container plants as long as you have a container big enough for these flowering shrubs. You can change your hydrangea colors quicker in a container because the soil is contained. You can premix additives into the potting soil before you even plant your hydrangeas if you know you will want to change the flower color!

For Blue Flowers

Add 1 tablespoon of soil acidifier for every 4 inches of container diameter, and repeat every 60 days or until you have the perfect shade of blue.

For Pink Flowers

Add 2-4 tablespoons of garden lime twice per growing season, once in the spring and again in the fall.

Final Thoughts 

The easiest way to grow beautiful hydrangeas in your yard is by purchasing what will work for you! Amending soil can be tricky, and its effects are only sometimes immediate. On the other hand, I understand the desire to have the truest blue hydrangea blossoms.

So, as long as you come prepared with a heap of patience, this process is definitely worth it. Gather your information and your supplies, and get started!

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