I've recently moved into a house with a hedge which we are fairly
certain is a potentilla fruticosa

I've searched the net and the library, and am thoroughly confused.
Various sources say it should pruned in spring and trimmed in winter,
or vice versa, or only pruned or trimmed in winter or spring and I'm
completely lost.

What is the difference (if any) between trimming and pruning ?

What should I be doing to it and when, because it's a pleasant hedge
and I don't want to kill it or let it get all straggly

thanks in advance

Mike

Mike, the 'correct' way to prune Potentilla is to take out one stem in three in
early spring. However, you say it's a hedge, so you might have to adapt the
pruning technique somewhat. I'd suggest that if you're happy with how it's
growing/flowering, just go over it with a hedge trimmer in early spring, and
maybe thin out some of the old/dead wood where possible. If the shrub is
really beginning to suffer from neglect and needs some rejuvenation, then it is
possible to hard prune it back to within about 15cm (6 inches) of the ground.

On a more general note, trimming is just a form of pruning. More correctly it
could be described as 'trimming to shape' and is what would normally be done to
Buxus sempervirens and other hedging plants. This pruning technique is just
one of 9 techniques, though some people may argue that there are more/less
techniques. It depends on how you classify the techniques.

I hope this is helpful. If you need some more advice on pruning I'd be happy
to answer any questions (if I can) and can point you in the direction of a few
good books if you want.

Dave.