How do I look after hydrangeas?
March is a good time to prune to ensure good flowering for next year.
If you have an old hydrangea in the garden and it has not been pruned for some time then it would be a good time to prune it right now. Cut back any old flower heads about 20 cm back on the stem. If you want the plant to flower again next year then you must leave a number of shoots that did not flower last year. Mulch the plant with well-rotted manure after pruning and give it a good soaking