"The Macrophylla hydrangeas called the Lacecaps and the Mopheads will flower on old wood, so all you need to do is remove the flower head, just above a couple of nodes, come spring, you should see ...

In warmer climates (or hardiness zones 4 and above), then you'll only need to do light winterizing ... is especially important for hydrangeas grown in porous containers, like unglazed terracotta ...