Hydrangea Flower Colourant

SKU: 57832

500g Bottle

Delivered in 3-5 days

Sale price£8.95

Hydrangea Colourant is ideal if you want to change pink hydrangeas to blue.

The blooms of Hydrangea macrophylla (common names include bigleaf hydrangea, French hydrangea, mophead hydrangea, and hortensia) and Hydrangea serrata (common names: lacecap hydrangea', 'tea of heaven' and 'mountain hydrangea') can change colour based on the amount of aluminium the plants absorb from the soil, which depends on the soil ph.

Hydrangeas that grow where iron or aluminium salts are present tend to change colour and produce blue flowers. Pale pink hydrangeas will turn blue, darker pink varieties turning to mauve or blue. It also depends on variety.

Best colours are achieved in acid soils (low pH), if you soil is alkaline (high pH) the recommended amounts of the colourant should be doubled.

Colourant can be used for both pot grown hydrangeas and those grown in borders.


Mix the powder with soil or dilute with some hot water. Water weekly during growing season.

Keep out of reach of children, wear gloves and eye protection during use.

Pot or container grown hydrangeas

Mix Hydrangea Colourant with the soil, of one part to thirty parts of potting soil for example 250g in 7.5ltr of compost. During growth water weekly with 30g Colourant per 5ltr 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 e.g. 250g in 7.5ltr of compost/soil. Water weekly during the growing season at a rate of 30g per 5ltr of water. Apply to the area of soil covered by the bush itself, thoroughly wetting the soil surface.

The colour of other plants (like : Rhododendron, Camellia, Azalea, Pieris, summer-flowering heathers (Calluna), Japanese maples - Acer) can be intensified by using Hydrangea Colourant.

500g bottle supplied.

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