There are several types of Hydrangea to consider. The Mop Heads or Hortensia above, the lace caps or other species. They are a rewarding group of plants to grow well but need the right conditions to excel.

Provide Suitable Growing Conditions

• All hydrangeas thrive in moist well drained fertile soil.
• Too wet and humid and you may get root rot and botrytis on foliage.
• Hydrangeas appreciate partial shade.
• Shallow chalky soil or light sandy acid soil may cause yellowing of leaves. To cure this water or foliar feed with Epsom salt (Mangenisum Sulphate).
• Hot dry conditions can encourage powdery mildew.
• Hydrangeas can be prone to insect attack from Aphids, Red Spider mite, Capsid bugs and even Vine Weevil.

 

Flowering Problems

• The main cause of non-flowering is pruning too hard and cutting off the buds. Just trim off the old heads in spring to the first fat buds.
• The failure of flowers to turn blue is caused by a shortage of trace elements of Aluminium. This is available in acid soils but not alkaline soils.
• Some species will change from pink to blue by using a proprietary preparation or colourant. This is unlikely to work when the soil is too alkaline.
• If you have a pink flower this can be enhanced by applying limestone or chalk during winter.
• White flowers remain white whatever you do. Some fade to a pink tinge.

 

Other Sources of information

Hydrangeas available from Thompson & Morgan

See Help to change Hydrangea colour
Hydrangea Hydrangea an enthusiasts site

Amazon for Hydrangea books