How to Keep Hydrangeas White (With Simple Care Tips)

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Having a variety of colors in the garden is something most gardeners want to achieve. I’m proud to have met that goal—my backyard is teeming with a vibrant array of hues, from cheerful daisies in bright yellow to delicate roses in soft pinks and vibrant reds. 

Out of all the bright, vibrant flowers I’ve planted, the one color that stands out the most is white. It’s no exaggeration when I say that white can tie together an entire garden, and there’s no better plant to fill that role than white hydrangeas. 

Hydrangeas possess a unique ability that most flowers (likely) envy: they can change their color based on certain factors. 

However, this ability has a downside. If you’re not careful and don’t maintain your hydrangeas properly, they can shift from pure white to beige or light pink, which can disrupt a planned color scheme or aesthetic in your garden.

Also see: What to Plant with Hydrangeas (Companion Planting Guide).

Because of this, understanding how to keep hydrangeas a particular color is the first step in knowing how to keep your white hydrangeas their snow-white color.

Keep in mind that while you cannot intentionally change a white hydrangea to blue or pink, the color of the blossoms can shift to a light pink or tan. This change isn’t welcome for those specifically aiming for a pristine white appearance.

How Do Hydrangeas Keep Their Colors?

Hydrangeas are a curious type of plant, with their colors often changing because of the pH of the soil.

If there’s a change in the soil content for blue or pink hydrangeas, there’s a good chance that the color of their blossoms will also change. This makes them an incredibly popular type of flower among gardeners of all kinds.

However, white hydrangeas are slightly different than their blue and pink counterparts. Unlike most hydrangeas, white ones are going to stay white for as long as they’re healthy and alive. They’re not affected nearly as much by the pH of the soil as the other colors are.

Check the price of Incrediball Smooth Hydrangea Shrub on Amazon.

In fact, the only time that they begin to change color is when their blossoms are growing old and dying. The blossoms will turn to a pink, tan, or blue color, depending on the genetics of the flower itself.

This isn’t to say that you can just leave your hydrangea in the nearest pot of dirt you find. You should still make the effort to give it its preferred pH of the soil and make sure that it gets all the nutrients that it needs.

You simply don’t have to worry about micromanaging the pH of the soil to the extent that you need to for other colors.

Keeping Your Hydrangea Happy

Because the color of the hydrangea will change when the blossoms die, you will want to do everything you can to keep the blossoms alive.

Of course, there will come a time when the blossoms of the flower die of old age, but making sure that the plant is happy and healthy is going to be an important part of making sure the flowers stay alive for as long as possible.

First things first, you are going to want to work with the pH level of the soil. While white hydrangeas are not really affected by the pH of the soil, you should still try to keep it at its preferred level to keep it a happy and healthy plant.

You should test the pH of the soil (link to soil tester on amazon) to see where you are starting from. Your goal should be to get the pH of the soil between 6.0 and 6.2.

Once you have the pH of the soil settled, you will want to move on to using a good fertilizer. Fertilizer helps feed the plant the nutrients that it needs to keep it vibrant and happy. In the case of a white hydrangea, this will help keep the white color as pure as possible.

You will want to aim for using a balanced, slow-release fertilizer. This means you will want to look for a fertilizer that has equal parts of nitrogen, phosphorous, and potassium for your hydrangea plant.

After you have added the fertilizer, you should test the pH of the soil. It should be no higher than 7.0, although closer to 6.0 is going to be best for the plant’s colors. When you are applying fertilizer, you should remember to fertilize it once during the winter seasons.

Depending on how expansive your garden is, you are going to want to make sure that you are applying one pound of fertilizer per 100 square feet of soil, so that every plant in your garden can get the nutrients needed.

You should also consider placing a fair amount of mulch around the base of the plant. This helps to protect your hydrangea from all sorts of trouble that can come from unprotected soil.

Because the color of the hydrangea will change when the blossoms die, you’ll want to do everything you can to keep the blossoms alive.

Of course, there will come a time when the blossoms of the flower die of old age, but making sure that the plant is happy and healthy is an important part of making sure the flowers stay alive for as long as possible.

Test the pH Levels

First things first, you’ll want to work with the pH level of the soil. While white hydrangeas aren’t really affected by the pH of the soil, you should still try to keep it at its preferred level to keep it a happy and healthy plant.

To get started, test the pH of the soil to give you an idea of its acidity or alkalinity. Your goal should be to get the pH of the soil between 6.0 and 6.2.

Once you have the pH of the soil settled, invest in a high-quality slow-release fertilizer, with equal parts of nitrogen, phosphorous, and potassium.

Add the Correct Fertilizer 

Fertilizer helps feed the plant the nutrients that it needs to keep it vibrant and happy. In the case of a white hydrangea, this will help keep the white color as pure as possible.

After adding the fertilizer, test the pH of the soil. It should be no higher than 7.0, although closer to 6.0 is going to be best for the plant’s colors. 

Fertilize in early spring before the hydrangeas start growing a lot of leaves and flowers. Do it when you see the buds starting to get bigger, but before the leaves and flowers really start showing up.

Depending on how expansive your garden is, apply approximately one pound of fertilizer per 100 square feet of soil so that every plant in your garden can get the nutrients needed.

By giving the plant the care that it needs, you can rest assured knowing that the blossoms will retain their pure white color throughout the plant’s life.

Mulch Appropriately 

You should also consider placing a fair amount of mulch around the base of the plant. This helps protect your hydrangea from all sorts of trouble that can come from unprotected soil.

As for the exact type of mulch you will be using, aim for some shredded wood bark or a homemade compost mulch. These are going to be the best mulches to keep your hydrangea happy.

Regularly Water 

Finally, make sure that you are watering the plant regularly. More often than not, you can use the water hose and your hydrangea will be just fine.

You should make sure that you are not watering the plant so much that the water is standing on the soil, as excess water will bring rot to your hydrangea, and nobody wants that. 

The exact amount you will be watering the plant depends on the temperature and humidity in your area.

Final Thoughts 

In the end, keeping your white hydrangea happy, healthy, and protected is the best thing that you can do for the color of the plant. Just because it isn’t affected by pH levels as much as other hydrangeas doesn’t mean that you can slack off on the amount that you care for the plant.

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