Changing color of hydrangea

How to Change the Color of Hydrangeas

Love your hydrangea blooms but want to change up their color? Many hydrangeas will go through a slight color change when transplanted due to adjusting to their new soil when you first bring them home. But if you really want to shake things up, this simple little soil hack will make your hydrangea change color!

Keep in mind that this will only work for the blue or pink varieties (white blooms cannot be changed to any other color). And before you get too excited, you cannot change the intensity of the color; that is more dependent on the environment or weather. Although I must say that changing hydrangea bloom color so drastically is pretty darn exciting!

Soil Test

The first thing you need to do is test the pH of your soil. Acidic soil (lower pH) will yield blue flowers and alkaline (higher pH) will give you pink flowers. You can buy a soil test kit at your local garden center to determine the pH of the soil, but here is a quick and simple way to figure out your soil’s pH with ingredients from the kitchen.

Once you know the general pH of your soil, you can adjust it to get pink or blue hydrangea blooms.

How to Turn Hydrangeas Blue

If your hydrangeas are pink (because your soil is alkaline) and you want them to be blue, you need to make the soil acidic by increasing the presence of aluminum. You can achieve this by adding amendments to you your soil like pine needles, compost, coffee grounds, and aluminum sulfate that help make the soil acidic over time. Keep in mind that changing the pH of your soil is a gradual process and will not result in deep blue blooms overnight. It can take up to a year for the color change to happen.

If your soil is naturally alkaline, you’ll have to add an aluminum source throughout the growing season to keep them blue. If you are using aluminum sulfate, you will need to add 4 tablespoons of aluminum sulfate to a gallon of water, and drench around the base of the plant every 2 to 4 weeks.

How to Turn Hydrangeas Pink

To change hydrangea flowers from blue to pink, you need to remove the aluminum from the soil. The only way to do this is to add garden lime to soil to help raise the pH. Sprinkle 3 to 4 cups of garden lime around the base of the plant. Again, you will have to add the lime every 3 to 4 weeks throughout the growing season to keep the blooms pink.

Now that you know how to change the color of hydrangeas, head over to read about how to care for them in this Essential Guide to Hydrangeas.

And preserve the color once you have it with How to Dry Hydrangeas and Retain Color!

You Can Change the Color of Some Hydrangeas

There are many kinds of Hydrangeas available today. Maybe the plant breeders went a little crazy introducing new selections recently. The good news is there are a lot of Hydrangeas with new color options, smaller plants, and more flower power!

Nature Hills offers many options with some of the newest and the best.

There is one group of Hydrangeas with pink or red flowers that can be changed to blue or purple flowers by altering the soil pH. This group is called Bigleaf Hydrangeas (Hydrangea macrophylla) and the flower color can be changed by growing the plants in a lower soil pH.

There was a breakthrough with this species of Hydrangea that opened the door to growing them in colder regions. Then the plant breeders went to town introducing many new varieties with many new shades of reds, pinks, purples and blues. Some are mop head types with rounded flowers, and others are lace-cap flowers that are flat topped and the flowers open in a circle.

In general, these hydrangeas really prefer a slightly acidic soil higher in organic matter, mulch over the roots, and protection from the hot afternoon sun. Soil pH is the measure of alkalinity (higher) or acidity (lower) of the soil. You can buy pH test kits, or you can get soil from your local ag extension office to find out the pH and fertility levels – if you are interested in trying to change color at home.

Most of the production nurseries are growing these plants by treating the soil with aluminum sulfate or soil sulfur. The flowers that are produced in the lower soil pH are lavender, purple, or blue – or even a mix of these colors.

Some areas of the country naturally have a lower soil pH and those same Bigleaf Hydrangeas exhibit the blue and purple colors naturally. Maybe those same Hydrangeas are more pink and red at your home? If that is the case, then you can change those colors by treating the soil of your Hydrangea macrophylla.

Have you seen all the amazing selections available today? Smaller plants that re-bloom, and bloom for longer periods of time are leading the pack. Remember that only Hydrangea macrophylla types are the ones that you can change the flower color. In Hydrangea arborescens types (like the old-fashioned Annabelle types), flower color is not affected by the soil it is grown in. The same holds true for Hydrangea paniculata selections that are so popular, as well as Hydrangea quercifolia. These plants are not affected by the soil pH, but the flowers all do a bit of changing as they age and eventually dry and remain on the plants.

A simple way to change the color of your Hydrangea macrophylla selection is to add 1 tablespoon of aluminum sulfate mixed with a gallon of water and use that to water your plant throughout the growing season – a couple of cups each week or so. This simple method will help keep the soil pH lower and the blue and purple flowers coming on. When watering your plants with this mixture please be sure that your plant is not completely dry when you apply the aluminum sulfate as it could burn the roots. Keep your hydrangea roots watered and then apply the solution the next day to prevent any issues.

Hydrangea Color – How Do I Change The Color Of A Hydrangea

While the grass is always greener on the other side, it seems the hydrangea color in the yard next door is always the color you want but do not have. Not to worry! It is possible to change the color of hydrangea flowers. If you have been wondering, how do I change the color of a hydrangea, keep reading to find out.

Why Hydrangea Color Changes

After you have decided that you want to make your hydrangea change color, it is important to understand why hydrangea color can change.

The color of a hydrangea flower depends on the chemical makeup of the soil it is planted in. If the soil is high in aluminum and has a low pH, the hydrangea flower will be blue. If the soil has either a high pH or is low on aluminum, the hydrangea flower color will be pink.

In order to make a hydrangea change color, you have to change the chemical composition of the soil it grows in.

How to Make Hydrangea Change Color to Blue

More often than not, people are looking for information on how to change color of hydrangea flowers from pink to blue. If your hydrangea flowers are pink and you want them

to be blue, you have one of two issues to fix. Either your soil is lacking in aluminum or your soil’s pH is too high and the plant can’t take up the aluminum that is in the soil.

Before starting a blue hydrangea color soil treatment, have your soil around the hydrangea tested. The results of this test will determine what your next steps will be.

If the pH is above 6.0, then the soil has a pH that is too high and you need to lower it (also known as making it more acidic). Lower the pH around the hydrangea bush by either spraying the ground with a weak vinegar solution or using a high acid fertilizer, like those made for azaleas and rhododendron. Remember that you need to adjust the soil where all the roots are. This will be about 1 to 2 feet beyond the edge of the plant all the way into the base of the plant.

If the test comes back that there is not enough aluminum, then you need to do a hydrangea color soil treatment that consists of adding aluminum to the soil. You can add aluminum sulfate to the soil but do so in small amounts through the season, as this can burn the roots.

How to Change Color of Hydrangea to Pink

If you would like to change your hydrangea from blue to pink, you have a more difficult task ahead of you but it is not impossible. The reason that turning a hydrangea pink is more difficult is there is no way to take the aluminum out of the soil. The only thing you can do is try to raise the pH of the soil to a level where the hydrangea bush can no longer take in the aluminum. You can raise the pH of the soil by adding lime or a high phosphorus fertilizer to the soil over the area where the hydrangea plant’s roots are. Remember that this will be at least 1 to 2 feet outside the edges of the plant all the way into the base.

This treatment may need to be done repeated to get the hydrangea flowers to turn pink and once they do turn pink, you will need to continue doing this hydrangea color soil treatment every year for as long as you want pink hydrangea flowers.

How Long Does It Take to Turn a Pink Hydrangea Blue?

Steve Bender

Many people ask me how to turn their pink hydrangea blue – a lot more than ask how to turn a blue hydrangea pink (the South loves the blues, I guess). I answer just like every other know-it-all.

The flower color of a French aka bigleaf hydrangea (Hydrangea macrophylla) depends on whether the soil is acid (below pH 7.0) or alkaline (above pH 7.0). Strongly acid soil of 6.5 or below produces blue flowers; alkaline soil produces pink or red flowers; and near-neutral soil of pH 6.5 to 7 gives you purple flowers or a mixture of blue blooms and pink ones.

How do you change the soil pH? To make it more acid, you add sulfur. To make it more alkaline, you add lime. Easy-peasy, right? Not so fast.

Some hydrangeas change color easily. The original ‘Endless Summer’ is one. I bought one that was blooming pink in the pot, planted it into my strongly acid soil, and the next year it bore bright-blue flowers. In a neighbor’s yard with near-neutral soil, half of its flowers were blue and half were pink.

My ‘L.A. Dreamin’ hydrangea (above) is another matter. I was smitten the first time I saw it out in California. Big blooms in colors of blue, purple, and pink smothered it. It also blooms on both old and new growth, so even if winter kills the flower buds or you cut them off by pruning at the wrong time (fall and winter), you still get blooms.

‘L.A’ Dreamin’ performed admirably for me in a big container (hydrangea are great container plants BTW, but that’s a future story). The flowers emerged bright-pink, slowly aged to nearly red, and lasted for months. I ended up drying the last flowers indoors. My only quibble is I wanted a little more blue, a little more purple.

I turned to Espoma Organic Soil Acidifier which contains 30% sulfur. (I’m a big fan of Espoma products and they didn’t pay me to say that. I bought the bag.) The label recommends sprinkling about 1-2 cups around the plant and watering it in. Repeat at 60-day intervals until you get the color you want.

My hydrangea just received its third application and I’m still waiting for the first sign of blue. I think it will happen. I’ll just have to take the same advice I so often dole out to you. Be patient.

WATCH: Easy Ways To Change Hydrangea Colors

One more factor in this people seldom consider is their water quality and its pH. Hard water contains lots of dissolved minerals like calcium and magnesium and is alkaline. Soft water contains few minerals and is acid. So if you’re watering your hydrangea with hard water, changing the flower color from pink to blue is going to be a longer and ongoing process.

That’s life.


The color of your hydrangea flowers is determined by the acidity of the soil they’re planted in. That is it. That’s the only reason. So if you wander into Costco looking to buy yourself some pillow case sized bags of potato chips, half a cow, 35 bottles of Windex and a jar of pickles big enough to drive … don’t pass up on the potted pink hydrangeas just because they aren’t blue. You can change that. You can turn your pink hydrangeas blue.

(Speaking of potato chips did you try a new food? Did you send me a photo of it? A blog post featuring allllll the new foods you tried (the good, the bad, and the ugly, coming up in a week or so! Don’t forget to include a little description of what you made and why in the email. Send photos to [email protected])

Generally speaking you can turn those pink hydrangeas blue just by changing the acidity o the soil they’re in and if they’re in a container it’s even easier to do. Problem is, you can’t change the colour that the flowers are once they’ve bloomed. What you have to do is change the acidity of the soil before the flowers bud and bloom.

It’s not hard but you do have to buy one special ingredient. Love. Just kidding. You can’t buy love unless you’re Rupert Murdoch.

What you do need to buy is Aluminum Sulfate, which sounds like the kind of thing you could only find in a lab, but you can find it right there in gardening aisle of your local hardware store, or garden centre. It’s perfectly safe (and in fact it’s used for purifying water) and it’s cheap.

If your hydrangea bush still looks like this you still have time to change the colour of your flowers. If they grow pink even though when you bought your hydrangea it was blue, this is why …

Soil that has a pH above 6.0 will produce pink hydrangeas. Soil that has a pH below 6.0 will produce blue hydrangeas. So if you bought a potted hydrangea that was blue, once you put it in your soil it didn’t have the proper acidity to grow blue anymore. So how do you know what the pH of your soil is? You can buy a little kit that’s like a pool testing kit to check the pH of your soil. You just put a little soil in the container, add the pH testing powder, some water and give it a shake.

I tested the soil around my hydrangea plant and it’s pretty off the mark for a blue hydrangea, with a pH of between 7 and 7.5. So that’s going to produce a very pink hydrangea. Which is nice, but it’s also nice to experiment a little. I want to try to get blue hydrangeas this summer which means dropping that pH to below 6.

Aluminum lowers the pH of soil so I need to add aluminum. Since crushing cans and turning them into powdered form seemed like kind of a pain, I just bought a container of Aluminum Sulfate. Adding this to soil is the easiest way to get a blue flower.

But honestly, you don’t need to test your soil for acidity. If your hydrangea flowers are pink, you know that your soil acidity is wrong for producing blue flowers, so just grab some aluminum sulphate (aluminum sulfate) and start stirring it into some water.

Add 1 Tablespoon of Aluminum Sulfate to 1 gallon (16 cups) of water and water the hydrangea. Do this once a month starting now (before the flower buds on your hydrangea start to form) and you’ll be closer to having blue hydrangeas than you were before.

I say “you’ll be closer to having blue hydrangeas” since I can’t guarantee this works because even though everything I’ve read about the subject says it will, I’ve never tried it myself. I have every reason to believe it will work though because I read about it on the Internet.


You can try doing this with other soil acidifiers like coffee grounds or pine needles but unless you have an almost pathological addiction to coffee, chances are you won’t have enough grounds to alter your soil pH enough to make a really vibrant blue.

It’s almost guaranteed to work if your hydrangea is in a pot because you’re dealing with just a small amount of soil that you need to change the pH of, but hydrangeas in the garden are a bit harder to fiddle with. Also you’ll never be able to turn a white hydrangea blue. This only works with hydrangeas that are already pink or blue. The only thing a white hydrangea might become is tinged with pink because of the soil acidity.

This method I’m talking about here is meant for turning a pink hydrangea blue. Hopefully.

I’ve watered my hydrangeas with this solution twice now and I’ll keep doing it once a month or so until I know if it worked.

I don’t like putting things on my blog here if I don’t know for sure that they work, but if it does indeed work that’s a whole summer of blue hydrangeas I’m cheating you out of. Now if it doesn’t work for you don’t blame me. I warned you. It’s not my fault. I’m in the same boat you are, trying it to see if it’s successful.

If it doesn’t work for you, you can just hop in your pickle jar car, drive over to the King of the Internet’s house and complain. He’s usually easy to spot in his front window. He’s often seen hopping around in flaming pants, knocking lamps off of tables with his nose.

Have you ever tried to explain a color of hydrangea to a client, or build an inspiration board for an event and just can’t think of the name of the hydrangea you desire? Well, I have quite the visual treat for you today! FIFTY photos of hydrangeas currently in season – provided by Susan of Hilverda De Boer!

Coco White Hydrangea

Hydrangea Magical Pearl Green

Hydrangea Schneeball white

Antique Green Hydrangea

Hydrangea Emerald Classic green

Hydrangea green Ivoor (classic)

Hydrangea pale green Schneeball Classic

Hydrangea green Verena Classic

Antique Blue Hydrangea

Hydrangea Blue You & Me Together

Hydrangea Elbtal (classic)

Hydrangea Elbtal Classic

Hydrangea Homigo blue

Hydrangea Lolly Pop BLL blue

Hydrangea blue Magical Diamond

Hydrangea blue Magical Diamond

Hydrangea blue green Magical Revolution

Hydrangea blue Pimpernel

Hydrangea Rodeo (blauw paars)

Hydrangea Verena – classic blue green

Hydrangea Verena blue

Antique Lilac Hydrangea

Hydrangea Elbtal (blue)

Hydrangea Elbtal Classic

Hydrangea glow alps purple lilac

Hydrangea glow alps

Hydrangea Pimpernel Antique blue

Hydrangea Rodeo (classic)

Hydrangea Rodeo purple

Hydrangea Rodeo purple

Three Tone Antique Pink Hydrangea

Hydrangea Verena – pink

Hydrangea Terracotta

Hydrangea Rodeo (classic) – pink green

Hydrangea Rodeo (Cherry)

Hydrangea Magical Rubyred (classic) lilac

Hydrangea Magical Rubyred (classic) burgundy

Hydrangea Magical Revolution – pink

Hydrangea Lolly Pop RZ – Pink

Hydrangea glow alps rose – dark pink

Antique Red Hydrangea

Green Red Hydrangea

Hydrangea Beautensia Papillon

Hydrangea Beautensia Papillon

Hydrangea Magical Amathyst (classic) – Green Red

Hydrangea Magical Revolution (classic) – red green

Hydrangea Opal Classic – red green

Hydrangea Opal Classic – red green

Hydrangea Suzanne (classic) – green red

Hydrangea Opal Classic – red green

Additional notes on fall availability by Susan of Hilverda De Boer:
The ‘Fresh’ or Solid/Spring color season is really in the ‘off’ season time, however growers still have limited production available…. So this means smaller heads, limited production and higher prices.
The Purples of course are still in high demand, however common complaint is that heads are small and prices high… this is typical for a spring color hydrangea in fall production sadly. I do always encourage our clients to write a note to remind themselves for next year October weddings to get a premium price for purple hydrangeas and to expect them to decline in head size from the previous September month 🙂

White (Schneeball) and certain varieties (like Lollypop and Magical Revolution series) which are strongest in the spring season are still around, however are especially small in late season. These varieties are known to be a more compact smaller headed varieties in the best of season, however in late season it becomes even more pronounced in the compact sizing.

However the Antique season is strong… many muted and mingled hues of greens, burgundies, smoky rose and amethyst. Supply is steady throughout October. November and December will decline to mostly the Green/Red variety. The Dutch Hydrangea season then will go off season completely until next year April when the ‘Fresh’ Solid color season will return bursting with Spring vibrant colors !

If you have additional questions or would like to place an order please contact Susan at: 888-220-7248 or [email protected]

Can you change the colors of hydrangea flowers? It depends on your type of hydrangea and your soil pH. We’ll explain how to change color from blue to pink or from pink to blue.

Which Hydrangeas Change Color

It’s not every hydrangea that changes color. The color of some Bigleaf hydrangeas (H. macrophylla)—especially Mophead and Lacecap types—and H. serrata cultivars change color based on the pH of your soil.

Blues are best grown in acidic soil; pinks and reds do best in alkaline or neutral soil. In other words, acidic soils with a pH of less than 5.5 produce blue flowers; soils with a pH greater than 5.5 produce pink flowers.

White hydrangea color is not affected by the soil pH. The whites stay white (color can never be changed) and usually prefer the same conditions as the pinks and reds.

But the relationship between color and pH is more complex than just numbers on a scale. It is the availability of aluminum ions—and the degree to which a particular cultivar can absorb them—that influences color.

How Long Does Color Change Take?

It is possible to change colors, but not instantaneously. Color correction takes weeks—even months—for the desired changes. It is easier to change blue flowers to pink than to change pink flowers to blue, and some cultivars are more prone to color variability than others.

We recommend waiting until the plant is at least 2 years old to give it time to recover from the shock of its original planting.

Have your soil tested for pH, then check with your local nursery for the recommended amount of aluminum sulfate and directions. Here are a few guidelines to follow, once you’ve given a plant time to recover from the shock of its original planting:

How to Change Hydrangea Color

Knowing all of the above, it’s fairly simple to increase acidity (for blue) or alkalinity (for pink):

To Go Blue

To increase acidity (for deeper-blue flowers): Apply a solution of 1⁄4 ounce aluminum sulfate per gallon of water three times per year. (Aluminum sulfate is a colorless salt obtained by the action of sulfuric acid on hydrated aluminum oxide. Buy in any garden center.) Soak the ground with the solution after the plant starts growing in the spring and repeat twice at 3- to 4-week intervals. Once a year, in the spring, apply 25-5-30 fertilizer, according to manufacturer’s instructions.

To Go Pink

To increase alkalinity (for changing blue flowers to pink): In the spring or fall, spread ground limestone (dolomitic lime) at a ratio of 4 pounds per 100 square feet and water it well. (Excessive alkalinity will cause chlorosis, or yellow leaves.) In the spring or fall, apply 25-10-10 fertilizer, according to the manufacturer’s instructions.

Other Factors

  • Hydrangea flowers will naturally fade and dry in the fall, often to a combination of pink and green or tan. This is simply the aging process, which cannot be reversed.
  • Hard water can also affect the flower color, turning blue flowers more pinkish, so use rainwater to water your hydrangeas, when possible.

See our free Hydrangea Growing Guide for your complete guide to planting, growing, pruning, and caring for hydrangeas.

How to Change the Color of Your Hydrangeas

Related: Seven Show-Stopping Flowering Shrubs for Your Garden

Check the Variety

You can only change the color of a bigleaf hydrangea. “Other types of hydrangea cannot do this,” McEnaney warns. So, if you’re purchasing a hydrangea for the first time and want to change its natural hue, make sure you buy a bigleaf variety, he says.

Check the PH

Now, here’s how it works: “Acidic soil, with a pH below 6.0, will promote blue blooms,” says McEnaney, “and alkaline soil, with a pH above 6.0, will promote pink blooms.” (You can find your soil’s pH with a kit you can purchase at your local gardening home center or nursery, or from an online retailer. You’ll get a number from 0 to 14.) “If your soil pH is on the extreme ends of the spectrum, you can get even deeper colors,” McEnaney explains.

How to Change Color

If you find you have acidic soil—meaning your soil’s pH is less than 6.0—and you would like to change your hydrangeas from blue to pink, “add garden lime, which is found at most local nurseries, or wood ashes” to your soil, McEnaney says. With alkaline soil—meaning you have soil with a pH of 6.0 or more—you can change your plant from blue to pink by adding a soil acidifier or aluminum sulfate, both of which can be purchased at your area garden center.

In either direction you take your plant, “the amount of additive needed depends on how far from basic soil—a pH of 6.0—you are,” he says. You may have farther to go on the spectrum from acidic to alkaline or vice versa—and you may need more addictive to move the scale.

Don’t Forget to Fertilize

No matter what you do, don’t forget to fertilize your hydrangea. Additives such as garden lime and soil acidifier do not replace fertilizer, McEnaney says. “They are separate additives with different purposes, so be sure to follow fertilizing instructions in addition to the color-changing treatment,” he says, to ensure you have both the brightest and healthiest blooms.

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