Rosa Rugosa

My RHS book reckons that just removing dead, damaged, diseased or weak wood is sufficient to keep your rose healthy, although you can tidy it up with a VERY light prune. However, it also comments that an older shrub would benefit from removing some of the old main growths to the base each winter to encourage new basal growth. So it really depends on how old your rose is as to whether you want to begin to remove any old 'stems'.

Prune to keep in unde rcontrol but try not to 'fiddle' round the edges, take out a third of the branches from low down every year. This keeps a supply of new growth coming and keeps the plant young.