It succeeds every time

They are the favorite flowers that can be found in our grandmother's yard and, if you have ever wondered how they are purple one year, blue one year and pink the third, the answer lies in a trick…

If you want your hydrangea to have blue-purple flowers, the soil around it should be more acidic.

Acidic soil will help transfer aluminum to plants, which will cause a blue color, reports the Telegraph.

In fact, the blue flower can be obtained if you water the hydrangea every 7 to 14 days with the already mentioned aluminum sulfate.

The same can be achieved if pine needles, coffee grounds and the like are added to the soil.

If your hotensia is blue, then this means that the soil around it is too acidic.

Organic fertilizers will help to further acidify the soil.

You can make compost from your kitchen scraps like coffee grounds, banana peels.

You can add ash, crushed eggshells or special fertilizers based on phosphorus to the soil.