Originally, blue hydrangeas may discolour because the soil is not acidic enough. Colour your hydrangeas blue again with Pokon Hydrangea Blueing fertiliser. After using Pokon Hydrangea Blueing fertiliser, discoloured leaves of the blue-coloured hydrangea will be as beautiful again in the next flowering period as they were at the time of purchase.Preferably, treat the plant in the evening, when the sun is no longer so strong. For best results, treat your plants once or twice a year, preferably in the autumn - September or October - and a second time before flowering in the spring.1. Measure the correct amount of feed.2. Dissolve the powder in a watering can.3. Pour it on the soil around the hydrangea.Pokon Hydrangea Blueing fertiliser works best when dissolved in water. You should then use 10 grams per litre of water. If necessary, it can also be sprinkled around the plant in this case, use 15 - 20 grams, depending on the size of the plant. The dosage can be measured using the enclosed 10 grams measuring spoon.