These are my 3 hydrangeas today, having been pruned at the end of March. ‘Bluebird’ and the white mophead are superb, but the lacecap in B2 seems to be all foliage and no flower.

The lacecap in B2 has looked much better in the past (August 2017), but I can’t remember how I pruned it for this effect. It’s likely I pruned it to the ground whan I made the garden in late 2015 / early 2016. Perhaps it flowers on old wood, and what I should do is cut the stems which have flowered to the ground in spring, leaving new stems to flower later in the year.