Hydrangea: time to deadhead them.

Or is it?? It's late March as I write, and although we are having sunny days with a welcome increase in temperature, it's still perishingly cold overnight, with frost first thing. So is it time to deadhead the Hydrangeas yet? This is what they are commonly looking like, at this time of year: The dead flowers from last year are starting to look tatty, some of them are snapping and dangling…