Posted: 22/04/2014 at 21:04
It could have done with pruning earlier, but if you do it now you'll lose the blooms, which would be a shame.
What I would do is, after the first flush of flowers, instead of simply dead-heading I'd cut the stem back by about one-third, to a strong shoot, and top-dress the soil around with some Fish, Blood & Bone.
Next spring - for me usually mid Feb, depending on the weather and where you are, you can prune hard and rejuvenate the bushes.
For the future, there's a big advantage in uploading photos via the green tree icon, as we can click on the picture and enlarge it, so getting a much better look at what might be the problem.