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.
What natural solution will make my hydrangea blue?
The ability to transform the color of hydrangea blossoms from pink to blue is another trick apple cider vinegar has up its sleeve. In alkaline soil, hydrangea blossoms will be pink; in acidic soil, they will turn blue. Give the acid-loving plants a treat by combining apple cider vinegar and water.
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 use vinegar to make blue hydrangeas?
Although vinegar has a place in the home, does the garden need it as well? In order to alter the color of the blooms on bigleaf hydrangeas (Hydrangea macrophylla), some gardeners have begun using vinegar to lower the pH of their soil. Does this really function? The simple answer is, sort of; theoretically, it could. But is it the most effective long-term remedy for changing the pH of your soil? Here’s why we don’t believe it!
A Quick Chemistry Lesson
Did you know that the bloom color of hydrangeas isn’t directly influenced by the pH of the soil? It becomes a little trickier than that! In reality, bloom pigments are reliant on the presence of aluminum ions (Al+) in the soil. Aluminum ions react with hydroxide ions (OH-) in basic soils (pH > 7.5) to generate Al(OH)3, which is stationary in the soil and unavailable to plants. However, these aluminum ions are no longer bound by hydroxide and are free to mix with other ions when the soil becomes more acidic (pH lower than 6.5). Other ions, particularly those that plants absorb, will react with it. Aluminum is now “mobile” and available for plant uptake as a result. Hydrangea blossoms turn blue as they absorb more aluminum ions. Bigleaf hydrangeas can produce pink or blue flowers depending on whether the soil is acidic or basic.
While increasing the mobility of aluminum in your soil will alter the color of your blooms, it can also be harmful to your plants. A poisonous soil can have a pH that is too low. The plant may even perish if there is too much aluminum in the soil. To make sure you are not reducing the pH too much, make sure you test your soil frequently.
What does this have to do with vinegar?
Acetic acid, which makes up 5% of vinegar, is an acidic mixture of water. Since home vinegar has a pH of about 2.4, it is neutral at a pH of 7. (which is quite acidic). According to the hypothesis, adding weak vinegar to the soil will cause the pH to decrease sufficiently to alter the color of your hydrangea blossoms. The soil will become more acidic thanks to this tactic, but only temporarily.
Do we consider this to be a viable option? Not really, no. If it rains or is irrigated, the vinegar will quickly dissolve in the soil and have little effect on pH. Additionally, hydrangeas require a pH change that is sustained over a long period of time in order to change color. It might require more time than a single growing season! To keep the pH stable, you would need to add vinegar to the soil each time you water.
The best option for your plant or the local wildlife may not be this one. You may have heard that vinegar can be used to destroy weeds. Any leafy green tissue that vinegar is sprayed on will be destroyed because the acetic acid in vinegar can easily burn through the wax coating on leaves. When sprayed directly to the soil, the vinegar doesn’t hurt the roots. Pests like fungus gnats will be attracted to the vinegar’s pungent fragrance, while wildlife will be deterred from making your garden their home. Even worms and other significant soil creatures that are advantageous to your garden can be discouraged by it!
What are the alternatives?
Personally, we don’t advocate changing the pH of your soil because we believe hydrangea blossoms are lovely in every color. In the garden, a pH change can have a variety of effects, including making the soil unsuitable for neighboring plants. If you’re set on changing your bloom color, we advise using ground lime to raise pH levels or garden sulfur or ammonium sulfate to drop pH levels. Consider planting your shrub in a sizable pot because doing so is simplest in a container.
How can I restore the color to my hydrangeas?
Your blue hydrangeas’ color can be greatly improved by adding a small amount of aluminum sulfate. According to Myers, “the acidity of aluminum is what impacts the blue color of flowers.” “To brighten the blues of your flowers, consider adding aluminum sulfate or an equally acidic element like ammonium sulfate to the soil in alkaline soil, where there isn’t as much aluminum available to the plant.”
How can I dye my hydrangeas a dark purple color?
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.
Everyday Care of Hydrangeas
Make sure you are familiar with the ideal hydrangea daily maintenance. Both location and a nutrient-rich, well-drained soil are quite important. Never overwater them, and don’t fertilize them too frequently. Read my entire post to learn how to take care of hydrangeas. Get ready for the next phase once you have a firm handle on how to care for your hydrangea plants on a daily basis!
The Secret to Revive Hydrangeas
Your hydrangea bushes can be revived with a top-secret chemical, but I’m going to tell you what it is! Although you’ve probably never heard of it, you already have the secret ingredient in your kitchen. Have you prepared? It’s baking soda, of course!
A Little Goes a Long Way
The key is baking soda, but be aware that a little goes a long way. Mix 1 tablespoon of baking soda with 2 cups of water and use it to revive your hydrangeas that have withered. Make sure the baking soda completely dissolves by stirring. Note: This dose is sufficient for 3–4 hydrangea shrubs.
Every two weeks, apply this baking soda treatment. If you only have one hydrangea plant, you can apply the therapy to other weak plants and still get similar results.
Enjoy Thriving Hydrangeas!
You should start to notice more strong hydrangeas in a week or two. The plants start to produce flowers that are fuller and healthier.
Try baking soda if your hydrangeas just aren’t impressing you like they should. Try baking soda in the rest of your garden while you’re at it as well!
Note from the editor: This article was first published in July 2017. The information has been revised.
How can I maintain a blue hydrangea?
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 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 blue hydrangeas result 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.
Can hydrangeas be harmed by vinegar?
Some common plants, like rhododendrons, hydrangeas, and gardenias, thrive on acidity, making a little vinegar the greatest pick-me-up. However, vinegar can be lethal to many common plants. The next time you water these plants, mix one cup of unflavored white vinegar with a gallon of water to get fantastic results. For plants that don’t like acidity as much, you may also add some distilled vinegar to your soil to combat lime or hard water.