Posted: 01/01/2014 at 17:47
Hiya janebell, ??ou did the right thing, viz., pruning the flowered stems but did you take them back to the base?
Cuttting back every year immediately after flowering should initiate fresh new stems.
First thoughts are, of you did prune right back, are....do you feed too much or is the soil very rich? Or is your plant growing in too much shade?