We cut back the dead top growth at any time from the middle of this month onwards. We leave it on over winter to protect the crown of the plant from the cold. They need a moisture retentive soil as in dry conditions they get terrible mildew. If your soil is not fertile then feed with a general purpose fertiliser or one formulated for Roses (Tonk's Rose Fertiliser say) about now.

yep I agree owdboggy. Mine will get done next weekend weather permitting.