If you can only grow pink hydrangeas it's probably because your soil is too alkaline as this can determine flower colour. Used diluted in water or simply mixed in soil or compost this soluble colourant will encourage blue flowers on your prized plants. Suitable for outdoor or pot grown hydrangeas. Contains Aluminium sulphate. Use weekly for best results.
Directions for Use
Hydrangeas growing in the presence of iron or aluminium salts will tend to change colour and produce blue flowers.
Varieties that are naturally pale pink tend to turn blue the best, while the darker pink varieties turning to mauve/blue
Best results are obtained with plants growing in acid soil and if the soil is alkaline then you should double the following proportions.
Pot or Container-Grown Hydrangeas
Mix Hydrangea Colourant with the soil when potting in the proportion of one part to thirty parts of potting soil. During growth water weekly with 30 g Colourant per 5 litres of water.
Hydrangea Colourant is most readily dissolved first in a little hot water.
Outdoor Grown Hydrangeas
On planting, mix Hydrangea Colourant with soil in which the root system will develop, in the proportion of one part Colourant to thirty parts soil.
Subsequently, water weekly during the growing season at a rate of 30 g per 5 litres of water. Apply to the area of soil covered by the bush itself, thoroughly wetting the soil surface.
The colour of other plants can be intensified by treating with Hydrangea Colourant in the same manner.