Personally l cut back any old flower stems and any particularly manky leaves. In the Spring l check them over removing any dead leaves and tidy them up.
I find trimming off the old flower stems as they finish flowering through the warmer months of the year makes them produce fresh flower stems. I have only ever trimmed off the old flower stems and left the leaves tend to themselves and they have been doing well in the garden here for a number of years now.
Posts
for the fag ends of the aristocracy.
S.Yorkshire/Derbyshire border