How to grow hydrangeas

Hydrangeas are deciduous hardy shrubs. There are many different types of hydrangea, including mophead hydrangeas with their huge flowerheads and lacecap hydrangeas which have smaller more delicate flowers. The word hydrangea is derived from the Greek word hydor meaning 'water' and angeion meaning 'vessel'.

All photos by Toni and Diane Abram.

Hydrangeas should be planted in spring after the last spring frost or in autumn before the first winter frost. They can be grown in pots or borders and should be planted in a partially shaded, sheltered spot, in moist but well drained soil. 

I have mine planted in a spot that is in full sun for much of the day. This is definitely a case of  'don't do as I do.' As happy as my hydrangea is, it can struggle on very hot days. It is however very good at communicating it is thirsty, with the flowers going floppy and sad looking, however within a short time of watering, the plant perks right up again. 

I have a blue hydrangea which I have worked to keep that way by planting it in ericaceous soil and using hydrangea colourant, which can be purchased from a garden centre or online and can either be sprinkled around the base of the plant or added to water. The flowers on my plant range from dark inky blue, light blue, purple, lilac and lavender, all on the same plant at the same time.

I also have a pink hydrangea, which I got by taking a cutting of my blue hydrangea and planting it in general purpose compost. The colours of the flower on this plant also vary and change throughout the lifetime of the flower. 

While changing the colour of hydrangea flowers is possible, it isn't instant and not every hydrangea will change colour. It should also be noted that it’s easier to change blue flowers to pink than pink flowers to blue.

As the flowers of a hydrangea fade (they tend to go a bit grey when they are past their best), they should be deadheaded to encourage more flowers. During late summer, it is also easy to take hydrangea cuttings and you can learn how to do this below.

• How to take hydrangea cuttings 

Hydrangea flowers are attractive over the winter months too and they will help protect your plant from frost damage, if you leave them over the winter months.

Common problems

There are few pests and diseases to be concerned about when growing hydrangeas. Those grown in pots may be prone to vine weevil attack and some plants can be damaged by frost as described above. Powdery mildew, leaf spot wilt and blight can also appear on hydrangeas. Common pests include aphids and red spider mites.

Further information

• How to grow hydrangeas (Gardeners' World)
• How to grow hydrangeas (Thompson and Morgan)