Answer: Old roses should be pruned lightly. If the rose blooms once per season, prune after flowering, if it is a repeat bloomer, prune in winter or early spring. If what you have is indeed 'St. John's' it is a very, very old "species" rose. It requires only a light trim to shape and remove dead wood (which you can recognize due to it's "shaggy" and brittle appearance). It's natural, flowing growth habit is part of it's charm.
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