A blue hydrangea is no different from a pink one, except for the color. However, this is not a negligible factor, as blue hydrangeas are very rare, and the shade is unique. It is no wonder that garden owners would prefer blue hydrangeas. The good news is that there is a clever trick that changes the flowers of your hydrangea into a wonderful blue color. Of course, it won’t happen overnight, but the results will be worth the time and effort.
Hydrangea is a peculiar shade of blue, which might be best defined as a color between violet and blue. The color of the hydrangea flowers is determined by the pH of the soil. In alkaline the soil, the plant produces pink flowers. To make the flowers blue – or to prevent blue flowers from turning back into pink – you need to increase the acidity of the soil.
You can use the following test to determine the pH level of the soil:
- Take a handful of soil.
- Place the soil in a small bowl and pour vinegar on it.
- If the reaction produces foam, the pH level of the soil is high, so it is an alkaline soil.
How to change the pH of the soil
Use organic ingredients to make the soil more acidic. For this purpose, you may use coffee grounds, crushed egg shells or ground lemon peels. Work these into the ground around the hydrangea and water well. You should add more coffee, eggshell or lemon peels from time to time. As an alternative, you may also use aluminum sulphate.