Mop head and Lace cap Hydrangeas - Hydrangea macrophylla types - better known as mop head Hydrangeas owing to their ball shaped flowers.
This group are the 'popular garden type of Hydrangea.
This section of Hydrangeas flower in mid to late summer on flowering shoots that were made the previous year. Correct pruning, at the right time will ensure that your hydrangeas flower well. They do not actually NEED pruning, but if you do, then the illustrations below show you how.
Hydrangea serrata Bluebird - A choice and popular lace cap variety of Hydrangea that falls within the method of pruning outlined below.
It is normal to leave the faded flower heads on the plant throughout the winter. They give added interest in the autumn, and protect the new buds below from severe frost damage.
In early spring, simply prune off last season's flower heads to about the first pair of healthy buds below the old flower head.
With older bushes, it would be a good idea to prune one or two of the main stems down to near ground level to encourage new growth from the base of the plant. This ensures continuous supply of healthy stems and usually results in larger Hydrangea flowers.