How to adjust the color of hydrangea

Hydrangea flowers in pure blue

Hydrangeas contain a type of anthocyanin that turns blue when combined with aluminum ions. However, when growing flowers, most soils do not contain aluminum, so the flowers are generally pink.

We can add some aluminum ions by applying aluminum sulfate fertilizer every 10 days before the hydrangea buds form. Alternatively, you can apply some ferrous sulfate solution or first-grade white vinegar to the hydrangea to keep the soil acidic and allow it to bloom blue flowers.

Hydrangea flowers turn blue, purple and pink

Sometimes, you can also see that hydrangeas are not of a single color, but multi-colored, mixed colors, and very beautiful. It's like a hydrangea with blue and pink flowers, the colors are gradient, it's very dreamy.

To make hydrangeas bloom in this color, you actually need to delay the time of fertilizing. After the hydrangeas slowly turn pink, use acidic fertilizers. This will change the acidity and alkalinity of the soil and the color of the flowers will appear gradual.

Hydrangea flowers turn purple

Hydrangea flowers can also bloom small purple flowers. When using acidic fertilizers for hydrangeas, use it before the buds form and stop after the color appears. In this way, the color of the flowers will change with the salinity of the soil. As the acidity gradually fades, it will become neutral or weakly acidic, and the flowers will be blue-purple.

Hydrangea flowers turn pink

In fact, what pink flowers need is alkaline soil. If the soil is alkaline when they are grown, there is no need to worry about it. If the soil itself is acidic, then you need to adjust it to alkaline soil by using alkaline fertilizer, such as sprinkling some wood ash.