The sought-after vibrant blue to purple flowers will be produced by high soil aluminum concentrations combined with an acidic soil pH. A variety of pink blooms will appear depending on whether the soil is alkaline or contains less aluminum. However, not all hydrangea species exhibit color variation. White variations remain the same, while others are bred to have a particular color scheme.
Before you get too excited, keep in mind that you cannot alter the hydrangea’s color intensity; it is more influenced by the surroundings or the weather. However, I have to admit that it is really thrilling to see the hydrangea bloom color change so radically!
Soil Test
Checking the pH of your soil is the first thing you should do. Pink flowers grow in alkaline soil, which has a higher pH, whereas blue blooms grow in acidic soil, which has a lower pH. You can purchase a soil test kit at your neighborhood garden center to ascertain the pH of the soil, but there is a quick and easy way to do it using items from your kitchen.
To get pink or blue hydrangea flowers, you can modify the pH of your soil once you know what it generally is.
Changing the Colour of Hydrangea Flowers to Blue
If your soil is alkaline and your hydrangeas are pink instead of blue, you must add more aluminum to the soil to make it more acidic.
To do this, amend your soil with things like pine needles, compost, coffee grounds, elemental sulphur, and gypsum, or feed your plants with an organic fertilizer containing cottonseed meal.
Adding aluminum sulphate to the soil is frequently not essential and may even be detrimental. Aluminum is abundant, not a necessary plant nutrient, and can be hazardous in large quantities.
Remember that altering the pH of your soil is a slow process, so don’t expect bright blue blooms right away. The color change may not occur for up to a year.
If your soil is naturally alkaline, adding an aluminum source will be necessary to maintain their blue color throughout the growth season. Sulfur is one of the most often used additives. Add 1/2 cup of sulfur per 10 square feet to utilize it. Every three months, repeat the procedure.
Changing the Colour of Hydrangea Flowers to Pink
You must remove the aluminum from the soil in order to convert blue hydrangea flowers to pink ones. The only method to accomplish this is to elevate the pH of the soil by adding garden lime.
Garden lime, a slow-release supplement for treating acidic soil, is crushed limestone rock. It has calcium carbonate in it, adding calcium while also bringing the pH of the soil up.
For every 10 square feet, sprinkle 1/2 cup of garden lime. Again, to maintain pink blossoms throughout the growth season, lime must be added every two months.
Lime: Does it turn hydrangeas pink or blue?
How many of you can recall the argument between the fairy godmothers in Walt Disney’s Sleeping Beauty about the color of the princess’ ballgown? Every time the traditional mophead hydrangeas (Hydrangea macrophylla) bloom in June, I recall that scene. The colors are the stuff of enchantment because they are so vibrant.
Aluminum, not a fairy godmother, controls the color of this hydrangea’s blossoms, whether they are pink or blue. Lack of metal results in pink blossoms, whereas an abundance of aluminum results in blue flowers.
For pink blooms, add lime to the soil; for blue blooms, add aluminum sulfate. The soil composition determines the required amount of lime or aluminum sulfate.
If you are adamant that your hydrangea will be pink or blue, plant it in a container where the pH of the soil may be easily controlled.
Is it possible to over-lime hydrangeas?
Large, deep green foliage and dense clusters of flowers with colors ranging from pink, blue, and white to red and purple are produced by hydrangea shrubs. The type of soil and its pH have a significant impact on the color of the bloom. To create pink or crimson hydrangea blossoms, apply lime to your soil in the early spring or late fall. Although it might be easier to apply lime to hydrangeas in pots, you can also integrate it into your garden soil to grow a bed of lovely pink French hydrangeas.
Dig a 6-inch-deep hole in the planting location, then remove some dirt. You may either test the soil yourself using a soil test kit or put it in a plastic zipper bag and mail it to your neighborhood garden supply store to have its pH value determined. Pink hydrangeas do best when the pH level is between 6.5 and 7.0. Lime will be added to the soil to raise the pH.
- Large, deep green foliage and dense clusters of flowers with colors ranging from pink, blue, and white to red and purple are produced by hydrangea shrubs.
- Although it might be easier to apply lime to hydrangeas in pots, you can also integrate it into your garden soil to grow a bed of lovely pink French hydrangeas.
Visit your neighborhood garden supply store to get lime. For every 100 square feet of ground, you should typically apply 2.5 to 5 pounds of lime, or 3 to 4 tablespoons for two to three medium-sized hydrangeas.
At soil level, sprinkle lime all around each hydrangea plant. Don’t sprinkle it on the plants’ foliage. Alternately, mix 1 gallon of water with 1 tbsp of hydrated lime and spread it over the base of the hydrangea bushes.
- Visit your neighborhood garden supply store to get lime.
- Pour it around the base of the hydrangea plants after adding 1 cup of hydrated lime to 1 gallon of water.
To make sure the lime reaches the soil’s roots, rake the area. Alternately, turn the soil over and shovel it in. When doing this, take care not to damage or disturb the roots. Mulch made of cedar should be placed over the soil.
Dig a hole the size of the root ball for each of your hydrangea plants before placing them in the ground. Each plant’s surrounding soil should be tamped down and watered until it is moist. Lime will be absorbed by the roots, resulting in pink blossoms on the plant.
- To make sure the lime reaches the soil’s roots, rake the area.
- Each plant’s surrounding soil should be tamped down and watered until it is moist.
Put time-breaking lime pellets in the soil. Every year, in the early spring or fall, add lime to the soil. This allows the lime to combine with the soil and break down before the growing season. Use only the amount that is specified. The plant may suffer damage or perhaps die if you overdo it. After adding lime, fertilize the soil a few weeks or even a few months later. The chemical composition of the soil is altered when lime is added. Verify that your hydrangeas don’t share space with plants that need acidic soil.
How often should lime be applied to hydrangeas?
Hydrangea plants must not absorb metal from the soil for the blossoms to be pink. If aluminum is present in the soil naturally, one should make an effort to keep it out of the hydrangea’s system. Here are a few techniques that might be effective: Add dolomitic lime on a regular basis. The pH will rise as a result of this. Aim for a pH of between 6.0 and 6.2. (If it goes above 6.4 hydrangeas may experience an iron deficiency). Raising the pH will help prevent the bluing effect of aluminum out of the hydrangea’s system since hydrangeas absorb aluminum best at lower pH levels.
Use fertilizer with a lot of phosphorus in it. Aluminum is kept from entering the hydrangea’s system thanks to phosphorus. Select a fertilizer with a ratio that is similar to 25/10/10. (Phosphorus is the middle number).
Consider growing pink hydrangeas in sizable pots in regions where blue hydrangeas grow naturally (soils containing aluminum). When growing hydrangeas in pots, it is recommended to use soilless mixtures because they are more likely to contain no aluminum. It will be much simpler to manage the conditions needed to cultivate pink hydrangeas in a pot.
What can you use to dye 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 soon do hydrangeas turn pink when lime is added?
Fall is the best season to apply lime to color hydrangeas pink. The lime must be incorporated into the soil and must be moist for the soil to react with the lime. First, sprinkle lime around the hydrangea’s base and work it into the ground with a rake. After washing off any lime that accidentally landed on the foliage with the hose to avoid burns, water the hydrangea slowly and deeply to activate the lime.
Third, get ready to have patience. The hydrangea’s surrounding soil will not instantly change color with the addition of lime. It can take months or perhaps three years, depending on the condition of the soil. Check the pH of the soil twice a year. The hydrangea won’t be able to absorb iron if it rises beyond 6.4, and it could get chlorotic. When fertilizing in the spring, add an iron supplement if the foliage becomes yellow.
If soil testing for a pink hydrangea reveal a high quantity of aluminum, fertilizer with a high middle number, such 10-25-10, should be used. This middle number stands for phosphorus, which aids in preventing aluminum absorption, which causes hydrangea blossoms to turn blue.
If you decide to force your hydrangeas to turn pink, keep in mind that it will take time. Your hydrangeas will likely turn blue again if you cease monitoring the pH level and the alkaline begins to decline.
How can I increase the size of my hydrangea blooms?
According to Enfield, certain varieties of hydrangeas develop larger blooms on their own and as a result require varying amounts of water and sunlight. It’s crucial to understand what kind of hydrangea you’re cultivating, she advises. “Bigleaf (H. macrophylla), which includes ever-blooming varieties, Smooth (H. arborescens), Panicle (H. paniculata), and Oakleaf are the four main classifications of hydrangeas (H. quercifolia). To determine what kind of hydrangea you have and how to care for it, look at the plant tags.”
What can I do to turn my hydrangea purple?
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.