How To Make My Hydrangea Turn Blue

The chemistry of the soil, not what is sprayed to the blooms, is what determines how colored hydrangea blossoms turn out to be. The color of the blossoms will increase with soil alkalinity. Some types stay pink at a neutral pH, while others begin to display exquisite lavender hues with undertones of blue. Acidic soils, usually with a pH of 5.5 or less, are ideal for blue hydrangea blooming.

Aluminum sulfate, which is readily accessible at practically any garden center, is the simplest way to acidify your soil and turn those babies blue. In the spring, as soon as the plant starts to grow, saturate the soil around your hydrangeas with a solution of 1/4 oz. aluminum sulfate in a gallon of water. Reapply in 4 weeks and again in 8 weeks because you’ll need to keep that acidity throughout the growing season.

Another, more organic way to increase soil acidity is to add organic materials like coffee grounds, egg shells, or citrus fruit peels. Simply break them up and till the soil with them. It can take a full year of doing this continuously for the changes to occur gradually, resulting in the proper acidity.

Do hydrangeas turn blue from coffee grounds?

  • Maintain low amounts of phosphorus, moderate levels of nitrogen, and high levels of potassium in the soil in order to make sepals bluer.
  • Maintain high levels of nitrogen and moderate amounts of phosphorus while adding garden lime to the soil to give sepals a pinker hue.
  • This should be completed in late autumn or early spring, well before flowering.

Can coffee grounds be used to change the color of hydrangeas?

Some gardeners claim that adding coffee grounds to the soil helped them successfully dye their hydrangeas blue. The soil becomes more acidic thanks to the coffee grounds, which makes it easier for the hydrangea to absorb metal. Fruit peels, grass clippings, peat moss, and pine needles are also believed to have a comparable impact.

Can eggshells be used to change the color of hydrangeas?

Crushed eggshells might be a good approach to grow pink hydrangeas. Eggshells will gradually degrade and lessen the acidity of your soil, which will make it more difficult for hydrangeas to absorb metal.

How do I make blue hydrangeas with vinegar?

To adjust the soil’s acidity and colour their hydrangeas blue, many gardeners add vinegar to their watering can. However, if you use Hydrangea Blue, a liquid fertilizer that yields blue flowers, you’ll probably get greater results.

How do I achieve a blue bloom on my hydrangea?

Grow the hydrangea plant in 5.2–5.5 pH soil to promote blue hydrangea blossoms. Applying Soil Acidifier at the rate recommended on the package will lower the pH if your soil is more alkaline. Applying an acidic organic mulch, such as pine needles or pine bark, can also lower soil pH (slower).

Even if there is a lot of aluminum in the soil, blue flowers will be very difficult to grow in soil that has a naturally high pH (alkaline). Aluminum is frequently “locked up” in alkaline soil, rendering it unavailable to the plant. (However, gorgeous pink hydrangeas can be grown!)

How are hydrangeas kept blue?

Although most plants may grow in a variety of soils, others require particular kinds of soil to thrive. Rhododendrons, azaleas, and other ericaceous plants require acidic soils in order to thrive. The soil in your garden must be acidic if they flourish there or in the gardens nearby. Rhododendron leaves turning yellow or disappearing from the area indicate that your soil is likely alkaline. In addition to affecting what you may grow, your soil type can also affect some plants’ leaf and blossom colors; hydrangeas are a well-known example.

Some hydrangea cultivars grow pink or red in alkaline soil and blue or purple in acidic soil. Therefore, if you plant a beautiful blue lacecap or mophead hydrangea in your garden and your soil is neutral to acidic, it will continue to produce blue flowers every year. Even if it was clear blue when you got it, it will flower purple-red or pink if you plant it in alkaline soil the next year.

It is challenging to keep beautiful blue blossoms alive in the open ground, but it is doable if you grow it in a pot; hydrangeas make wonderful topics for pots and containers. Select a pot that is attractive and big, at least 40 cm (15 cm) in diameter. Vitax Ericaceous Compost is the best growing medium for it; plant it there. If you consistently feed your hydrangea, it will thrive on this fertilizer that is specifically made for rhododendrons, azaleas, and other lime-hating plants.

Even though the growing medium begins out being free of lime, repeated watering in places with hard water tends to make it more alkaline. Therefore, add Vitax Hydrangea Colourant, a powder containing aluminum that you may mix with the compost, to ensure that your hydrangea stays truly blue. Each spring, you can also incorporate a small amount into the soil’s top layer and add it to the can when watering your plant.

White hydrangeas, incidentally, don’t change color depending on the type of soil, but they can blush pink in the light.

Feeding and watering

In pots, containers, and during dry spells in the open ground, regular watering is necessary since hydrangeas detest dry environments. When you plant your hydrangea in a bed or border, add lots of garden compost or farmyard manure, and make sure to water well both before and after planting.

The presence of food in the soil is necessary for hydrangeas to grow and produce flowers, even if they are not very demanding plants. In the open ground and in pots and containers, Vitax Conifer and Shrub Fertilizer should be used annually. This is ideal for acid-loving plants and won’t change the hydrangea’s color.

How can I turn my pink hydrangea into a blue one?

The question “How can I change the color of my hydrangeas?” pops up frequently in people’s minds. In contrast to most other plants, hydrangeas have intriguing blossoms that can vary greatly in color.

If hydrangeas could change color as readily as they do in this tiny image, that would be lovely. But it’s not simple for the majority of us. Those that cultivate their hydrangeas in pots have the most control over the color of their plants. In comparison to soil in the ground, it is significantly simpler to regulate or modify the pH of soil in a container.

On the other hand, when hydrangeas are planted or moved, their color frequently changes on its own. They are getting used to the new surroundings. One shrub may have numerous various hues the following year after planting, which is not uncommon.

A hydrangea may be changed from pink to blue considerably more easily than from blue to pink. A hydrangea’s color can be changed from pink to blue by incorporating aluminum into the soil. To go from blue to pink, the soil must either be depleted of aluminum or moved out of the hydrangea’s reach.

Having said that, I’ll present the most relevant information I currently have and let you decide where to go from there.

Commercial greenhouse hydrangea growers (as well as anyone else interested in this topic) should read the two notes at the bottom of this page.

How do I use vinegar to make blue hydrangeas?

Use apple cider vinegar diluted with water (20 parts water to 1 part vinegar). Water the plants at the base of them. The vinegar-and-water mixture might burn the leaves, so try to avoid getting it on them.

How much time does it take for hydrangeas to turn blue?

How is the pH of the soil altered? Add sulfur to make it more acidic. You add ground limestone, often known as lime, to make it more alkaline. Simple as pie, right? Wait a minute.

Some hydrangeas are quick to change color. One of them is the original “Endless Summer.” When I bought one that was blooming pink in the pot and placed it in my highly acidic soil, the plant produced bright-blue flowers the next year. Half of the flowers in a neighbor’s yard with nearly neutral soil were blue and half were pink.

Another issue is my “L.A. Dreamin'” hydrangea (see the picture above). It is also marketed under the name “Lindsey Anne,” which is the name of the breeder’s daughter. The first time I saw it in California, I fell in love. It was covered in large, multicolored blossoms in blue, purple, and pink. From early July to the end of the season, this 4-foot-tall shrub is in blossom. Additionally, it blooms on both old and new growth, so you can still obtain blooms on new stems even if cold destroys the flower buds or you prune at the incorrect time (in fall and winter).

In a large container, “L.A. Dreamin'” functioned admirably for me. The blossoms started off brilliant pink, grew over several months to almost redness. In the end, I dried the last of the blooms indoors. My only complaint is that I wanted a little bit more blue and purple.

I used Espoma Organic Soil Acidifier, which is safer than possibly hazardous aluminum sulfate and includes 30% sulfur. According to the package, you should scatter 1 1/4 cups or 2 1/2 cups of fertilizer around each new plant. For every 4 inches of pot diameter, a tablespoon is given to plants in containers. Water it in after evenly distributing the sulfur to the widest branches. Repeat until you achieve the desired hue at intervals of 60 days. Blooms that are violet-blue should appear at a pH of 5.5, whereas deep blue blooms will do so at a pH of 4.5. Flowers bloom in a more subdued blue at a soil pH of 5.0.

Do hydrangeas turn blue from rusty nails?

In reality, the presence or absence of a rusted nail or other rusting metal in the soil has no effect on how colored hydrangeas are. Many hydrangeas can transform from pink to blue without rusty nails being buried in the plant’s roots.

Are hydrangeas turned blue by epsom salt?

A: I’ve been considering the idea of using Epsom salts to intensify the blue hue of hydrangeas. I would like to attempt this as I have an old box of Epsom salts, but the term “salt” raised a cautionary signal. What percentage should I use?

A bitter salty spring in Epsom, England, where the water includes magnesium sulfate in solution, is where the name “Epsom salt” originates.

The term “salt” in chemistry simply refers to the outcome of an acid-base reaction. By combining sodium hydroxide and hydrochloric acid, sodium chloride (table salt) is created. The reaction between sulfuric acid and magnesium metal produces epsom salt.

Some salts, such as salt cod or Virginia ham, are particularly hydrophilic; they dry and preserve the materials they are placed with. Epsom salt does not absorb water from its surroundings since it is already hydrated.

The pH of the soil is left unchanged by the dissociation of the ions in Epsom salt. Since the metal that gives hydrangeas their blue hue is only present in acidic soil, adding Epsom salt won’t modify the color of your blossoms. Two tablespoons of alum (aluminum sulfate), which is acidifying, would have the desired impact on each plant.

Can you dye hydrangeas blue with baking soda?

Will hydrangeas’ color be altered by baking soda? One of the simple “tricks” that many people use to alter the color of their flowers is this one. Your hydrangeas’ color and appearance will change if you sprinkle some baking soda in the soil around them.

How can I get dark purple hydrangeas?

This traditional favorite is a must-have in any garden, and new cultivars have made hydrangea cultivation simpler than ever.

Generally speaking, blue or lavender-blue hydrangea flowers are produced by acidic soil, which has a pH lower than 6.0. Pinks and reds are encouraged by alkaline soil, which has a pH above 7.0. The blossoms turn purple or bluish-pink at a pH of 6 to 7.

Add aluminum sulfate or garden sulfur to your soil to reduce pH levels. Use ground lime to increase the pH. To ensure that the pH of your soil is within the desired range, retest it according to the instructions on the product you’re using.

Do hydrangeas respond well to vinegar?

People frequently ask for advice on how to change the color of hydrangea blooms from pink to blue. You have one of two problems to solve if your hydrangea blossoms are pink and you want them to be blue. Either your soil is deficient in aluminum, or the pH of your soil is too high, making it impossible for the plant to absorb the aluminum from the soil.

Have the soil around the hydrangea tested before beginning a blue hydrangea color soil treatment. Your next course of action will be determined by the results of this exam.

If the pH is higher than 6.0, the soil’s pH is too high, and you should try to bring it down (also known as making it more acidic). By applying a weak vinegar solution to the ground or using a high acid fertilizer, such as those designed for azaleas and rhododendrons, you can lower the pH around the hydrangea bush. Keep in mind that the soil around all of the roots has to be amended. This will extend from the edge of the plant all the way down to the base of the plant by around 1 to 2 feet (30 to 60 cm).

If the test reveals that there is insufficient metal present, you must do a soil treatment for hydrangea color that entails adding aluminum to the soil. Aluminum sulfate can be added to the soil, but do it gradually throughout the season as it can burn the roots.

My blue hydrangeas are turning green—why?

  • Because the color fades at the conclusion of the growth season, hydrangea blossoms turn green. Because the hydrangea requires less energy to create the pigments that give its flowers their blue, white, and pink hues, its blooms become green as the number of daylight hours decreases.
  • Heat and humidity are incompatible with the hydrangeas’ native habitat and are regarded to be a factor in the flowers’ alleged greening.
  • Some hydrangeas, including Hydrangea paniculata ‘Limelight,’ have naturally green blossoms that remain green all year long.
  • The typical occurrence of hydrangea flowers turning green does not indicate that there is a problem with the hydrangea. At the end of the flowering season, the blossoms typically start to wilt and turn green before turning brown.