Hydrangea Care Tips:

1. Water at a rate of 1 inch per week throughout the growing season.
2. Water with rainwater to keep hydrangeas blue.
3. Hydrangeas do best in moist soil and can wilt in hot weather, so keep well-watered during hot spells in summer.
4. Mulch hydrangeas every year in spring, with leaf mould, well-rotted manure, or compost. They don't need feeding, as this encourages leafy growth at the expense of flowers.
5. You can change the colour of the flowers on lace cap and mophead hydrangeas and Hydrangea serrata from pink to blue by feeding with a fertiliser low in phosphorous and high in potassium.
6. You can grow your plant in a pot of peat-free ericaceous compost and water with rainwater to keep the flowers blue.
7. Changing hydrangea flowers from blue to pink is trickier. You will need to raise the pH by adding dolomitic lime. It's quite common for a plant to produce a few different coloured flowers on one plant in the first year of growth. Few gardeners concern themselves with trying to change the flower colour – but it's interesting to know why plants may vary.

How to prune hydrangeas

Prune in mid-spring. They produce their flowers on old wood, so don’t prune them back hard, or this summer’s flowers would be lost. Traditionally, the old flowers are left on over winter as it protects the new growth beneath. Cut back the flower head to just above the top set of plump buds that are forming under the dead flower head. This is where the new flowers will form. If you have an overgrown plant, cut some of the stems off at the base.