Cut back, or leave standing? A hydrangea answer

A mophead cut back in March has been cut back to no flowers. Its buds formed last summer, at the tips of the stems you are holding the secateurs to.

Leave the old heads on through the winter -- they shelter the buds -- and in spring take off only the dead ones, just above the first fat pair of buds. The oakleaf is even simpler: leave it alone.