It’s Hydrangea season!
This stunning Hydrangea macrophylla Renata is usually blue in colour but will change colour with the pH of the soil. The more alkaline the soil, the pinker the flowers. The more acidic the soil, the bluer the flowers. To keep your hydrangeas blue, plant in a pot filled with ericaceous compost you can also add aluminium to the soil. Some people add aluminium can shavings to the soil but a hydrangea colourant is perhaps easier and available from our garden centres. To keep your hydrangea pink, use a fertiliser with high levels of phosphorus to prevent aluminium being absorbed. Fertilisers usually display content as NPK, P being the phosphorus so look for one in the ratio of 25/10/10