If you have bought a red hydrangea, you want to enjoy exactly this color of the romantic umbels. In this article you will find out why a red hydrangea suddenly has pink flowers and how you can turn the flowers of your hydrangea intensely red again.

The color of the hydrangea depends on the materials in the soil

Hydrangeas need acidic soil to absorb the aluminum necessary for the intense color. If the soil is only slightly acidic or slightly alkaline, the flowers of the hydrangea always turn a delicate pink.

A pigment from the anthocyanin group is responsible for the color of the hydrangea blossoms. The delphinidin forms a chemical compound with aluminum ions, which the hydrangea absorbs from the soil. This is shown by the red or, in very acidic soils, purple or blue coloring of the hydrangea umbels.

affect soil pH

In order for the flowers of your hydrangea to turn red, you have to shift the pH of the substrate to the alkaline range. It should be an average of 6 or even slightly higher.

Deacidify the soil with lime, which you spread around the plant several times during the growing season. In order not to lime too much, it is advisable to measure the pH value before the first application of lime and to repeat this analysis at regular intervals.

Dye a red hydrangea pink

Perhaps you are redesigning your garden and a red hydrangea no longer fits well into the overall picture. In this case, you can decolorize the hydrangea so that it will have soft pink flowers in the future. This works as follows:

  • If you have shifted the pH of the soil into the alkaline range, stop liming immediately.
  • The substrate is acidified by adding mature compost and a layer of leaf mulch.
  • Add a dash of vinegar to the irrigation water at regular intervals.

To prevent the soil from becoming too acidic, check the pH value of the vinegar water with test strips. We recommend that you also test the substrate on a regular basis. If the soil is too acidic, the hydrangea will not turn pink as desired, but blue with the appropriate aluminum content.

tips and tricks

Even with optimal pH, a red hydrangea will never turn as bright red as, for example, a rose. The color is always a bit pink.

Category:

Vegetable garden