The flower color of the hydrangea is an exciting topic for hobby gardeners. Changing the pH of the soil and adding hydrangea blue will change the color of the hydrangea. This allows interesting color accents to be set in the flower bed and the hydrangea adapts to the color design of the flower bed like hardly any other flowering perennial.

Acidic soil causes the hydrangea to turn blue

The soil is responsible for the color change

First of all, it is important to know that only pink hydrangea species are able to change color. The tint of the flowers is significantly influenced by these points:

  • pH of the substrate
  • aluminum content of the earth
  • Initial color of the flowers
  • hardness of the irrigation water

Achieve a color change towards pink

In order for a blue hydrangea to have delicate pink flowers, the pH must be shifted into the alkaline range. As a result, the plant also absorbs less aluminum and the flower color fades.

Lime the soil around the hydrangea several times a year until it settles to a pH of around 6. Fertilize the hydrangea twice a year with a special hydrangea fertilizer that also contains iron. This will prevent the plant from developing yellow leaves due to iron deficiency.

Sour makes you blue

The most desirable flower color for hydrangeas is a beautiful blue or rich purple. In order for the flowers to turn blue, the pH of the substrate must be acidic. At the same time, there must be enough aluminum in the earth.

acidification of the soil

Various means are suitable for this:

  • organic material (compost, peat)
  • Hydrangea or rhododendron soil
  • ripened crap
  • sulfur fertilization
  • water regularly with vinegar water

Increase the aluminum content of the soil

If the substrate has a pH of 5.2 to 5.5, you can apply hydrangea blue or aluminum sulphate. Check this value at regular intervals using test sticks, which you can obtain from specialist garden shops. Hydrangea Blue should always be used in the amount indicated on the packaging. If you prefer aluminum sulphate, you should dissolve two tablespoons of aluminum in five liters of water and water the plant with this mixture.

tips and tricks

Before treating with hydrangea blue or aluminum sulphate, the hydrangea must be watered well. This is the only way for the plant to absorb the coloring agent well.

Category:

Vegetable garden