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.
Will blue hydrangeas turn purple ones blue?
Pink and blue hues can be seen in both varieties of bigleaf hydrangea. Some are pastel, while others are deep and rich. You don’t always have to like the hue you receive, though. The amount of aluminum in the soil as well as the acidity of the soil affect the color and its intensity. This color change intrigues many gardeners, but it is more chemistry than magic.
Bigleaf hydrangea shrubs change color to blue when they take up aluminum from the soil. The more they take in, the bluer they get. The presence of these two conditions is necessary for the plants to absorb aluminum:
The soil contains aluminum. Because of the low pH, the soil is acidic.
What can I do to turn my hydrangeas 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.
How are blue or purple hydrangeas maintained?
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.
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 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.
Will hydrangeas become blue in vinegar?
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.
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.
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.
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.
What substances turn hydrangeas blue?
The soil needs to include metal if you want a blue hydrangea. Aluminum sulfate may be added to the soil surrounding the hydrangeas to ensure that aluminum is present.
Authorities advise applying a solution of 1/2 oz (1 Tbsp) aluminum sulfate per gallon of water to plants all during the growing season. The plants should be at least 2-3 years old. Important: Water plants thoroughly before applying solution, and use caution while applying it because too much might burn the roots.
The pH of the soil needs to be low in order for the plant to be able to access the aluminum (5.2-5.5). Aluminum sulfate will typically cause the pH of the soil to decrease. Adding organic matter to the soil, such as coffee grounds, fruit and vegetable peels, grass clippings, etc., is another way to reduce pH.
The hydrangea will naturally lean toward blue and/or purple tones if the soil is acidic (low pH) and naturally contains aluminum.
The color change will also depend on the fertilizer you choose. A good blue color can be achieved by using a fertilizer that is high in potassium and low in phosphorus (25/5/30 is good). The last number is potassium). When trying to make blue, superphosphates and bone meal should be avoided.
I hasten to add that if a hydrangea is planted in soil that contains no aluminum and is extremely alkaline, it is practically hard to turn it blue for any length of time (chalky). In order to maintain the soil’s above-mentioned good conditioning, one would need to be exceedingly diligent.
In a region with alkaline soil, growing blue hydrangeas in extremely large pots with enough of compost to lower the pH would be the best option. The bluing tips mentioned above would also apply to a potted plant. Aluminum sulfate strength should be decreased to 1/4 oz per gallon of water. It will be much simpler to manage the bluing requirements in a pot.
For those who are committed to this process, here is one more piece of advice. It’s crucial to have your water tested to ensure that it won’t “contaminate” the soil you’ve worked so hard to balance. No more than 5.6 should be the pH of the water.
It is difficult to grow blue hydrangeas when they are planted next to concrete foundations or sidewalks because the pH of the soil may be significantly raised as a result of lime leaching out of these buildings.
Does baking soda like hydrangeas?
Ever wondered what happened to your hydrangeas after going outside to check on them? They frequently appear unexpectedly exhausted and wilting, as if they are close to passing away. Your hydrangeas might even appear to get smaller every year. Here’s how to restore hydrangeas and make them seem gorgeous once more!
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.