Hydrangea Colourant

Keep your blue hydrangeas true blue with Hydrangea Colorant.

Blue-flowered hydrangeas that are growing in alkaline or chalky soils will gradually lose their beautiful blue colour and start to turn purple or pink. Similarly, blue hydrangeas growing in containers that are watered with hard water will also take on pink shades. Hydrangea colorant acidifies soils maintaining stunning blue flowers.

If your hydrangea has developed pink flowers and you want to change them to blue, Hydrangea Colorant is ideal. Pale pink hydrangeas will turn true blue whilst darker pink varieties will turn deep mauve-blue.

Best results are obtained with plants already growing in acid soils but if your soil is alkaline, double the application rate.

Please note: This hydrangea colourant is only effective on hydrangea macrophylla varieties. Some pink hydrangeas are bred to be pink regardless of the soil type and will not change colour. Always check the plant label.

How to use:
Dissolve 50g (10 teaspoons) of hydrangea colourant into 2.5 litres of water. Apply every month during the growing season, drenching the soil around the plant. The colourant can also be applied to container-grown plants using the same method.