I intend to prune my hydrangea RIGHT back this weekend
I am thinking the roots will then have less foliage to nourish through the winter months
Am I right in my thinking?
I'm assuming your Hydrangea is in the 'mophead' group (H. Macrophylia).
The usual advice with this variety is :- Dead head in march and remove any thin, weak branches at the same time.
Plus the fore-mentioned feeding and mulching.
Mopheads etc don't have any leaves to nourish in winter, they drop off. Do you have an evergreen variety? Anyway Spring is the right time to prune but you must leave some current year's growth. I always prune off the dead heads down to the next healthy shoot.