Hydrangeas are one of the ideal shrubs to grow in a pot, as long as it is a large container and we provide the irrigation care you need. It is a plant that in its mature age and on land, they say, can absorb up to 40 l of water per day, so that would be its main requirement. They also like half shade in summer but full sun the rest of the year. But let's move on to what you have come to look for in this note: change or maintain the color of hydrangeas.
What gives color to our hydrangea plant, are the modified bracts that surround the true flower of the plant. These bracts can be bluish, pink or white and their color depends on the conditions of the substrate on which it is growing, in addition to its variety.
Hydrangea is basically a plant that likes acid soils, although it can adapt to alkaline soils and this is where the color that will intensify in the plant is determined. For a quick guide, you should know that the greater the acidity, the more blue and more intense and the less acidic, the whiter or discolored.
A pH between 4.0 and 5.5 will give us blue hydrangeas.
A pH between 6.0 and 6.5 will give us pink hydrangeas.
A pH around 8.0 will give us white hydrangeas.
In this to change the color of hydrangeas, the key is to experiment. Although we have basic guidelines that indicate the requirements of the pH of the substrate and the minerals that hydrangea needs to produce a certain color (basically its aluminum content), there are endless elements that can make our experiment not work.
It is very important that you know that any modification you want to make to change the color of hydrangeas should be done at least two months before the flowering season.
Get blue hydrangeas.
As we said before, obtaining the color blue in a hydrangea depends, in the first instance, on the pH of the substrate that must be acidic (between 4.5 and 5.5). The other factor is aluminum that can only be absorbed if we have a sufficiently acidic pH.
So the first thing you need is to control the acidity of the earth and if it is not, make it acidic by adding for example: citric acid, vinegar, iron sulfate, and so on. You can read the article on how to change the pH of the substrate here in the blog.
Once we achieve our task of obtaining a pH of less than five, it is time to apply aluminum sulfate. The proportion to prepare it is dissolving 10 g of aluminum sulfate in 5 l of water and watering the hydrangea with this water twice a week about 60 days before flowering.
You should know that only hydrangeas support excess aluminum sulfate, this product is not suitable for use in other plants. It is also ideal to use rainwater, although aluminum sulfate will be largely responsible for neutralizing the lime of tap water.
When fertilizing, we will choose fertilizers rich in potassium and poor in nitrogen and phosphorus.
This treatment would serve both to maintain the color of the blue hydrangea you just bought and to turn a pink hydrangea into blue.
Finally, it should be clarified that you can buy directly in a nursery a product called "Hydrangea Azulator", but you must still control the pH of the soil.
Get pink hydrangeas.
Pink hydrangeas are the most common since the water with which we usually water our plants, comes from the tap, which has high lime content according to the area where we live. This constant irrigation with alkaline water, will remove the acidity of the soil and in this way our hydrangea stops absorbing the aluminum from the earth, turning pink.
If we want to convert the color of hydrangeas to pink, what we must do in the first instance is to decrease the acidity of the soil by raising the pH to a maximum of 6.5.
Get white hydrangeas.
First and foremost you should know that you will never achieve a pure white from a hydrangea that is pink or blue.
What you get by raising the pH to approximately 8.0 is to "clarify" the color of the flower so much that it looks white.
It is one of the most difficult things to achieve, so unfortunately, you just have to experiment.
Multicolored hydrangea bloom.
By carefully adding sodium carbonate to the soil, they say that multicolored flowering can be achieved.
Many times we naturally find different colors in the same hydrangea plant, the belief is that each branch absorbs nutrients differently, having in some areas more or less aluminum.
In order for us to modify the color of hydrangeas, it is necessary that it presents some shade of color at some point. A pure white hydrangea, like the ‘Annabelle’ variety, can never be colored, whatever we do.
And here we come, I hope I have clarified at some point the doubts you may have had about how to change the color of hydrangeas and especially that it has served you to take better care of your hydrangeas. As always, if you liked the note, do not forget to share it with your friends on social networks. Until next time.
