Modern HT and floribunda roses produce the best flowers on young bushes. In pruning, you aim to encourage the production of young wood from the base of the plant, which left to itself, would eventually become an unhealthy and untidy tangle of old, diseased and dead wood, shortening its useful life considerably.
In addition, all roses benefit from the removal of very old, woody branches, those badly positioned, and dead tissue which can become a breeding ground for all sorts of nasties.
Make all pruning cuts with clean, sharp secateurs to a position just above a bud (eye) pointing in the direction from which you want the new branch to grow. The cut should be slanting away from the eye at an angle of about 45 degrees, starting about \ in. (5 mm) above the eye. By this method, water drains off the cut away from the eye. Whole branches are best removed using heavy-duty sharp loppers or a pruning saw with a narrow blade. If possible, burn all prunings.
Shrub roses. These vary slightly according to species but can be left alone for several years apart from the removal of very weak, diseased, dead and dying growths and badly placed and crossing branches. You can remove the oldest, twiggy, flowered wood in autumn or spring, and the very strong shoots produced by some can be shortened by a third.
Miniatures. Just remove the old flower trusses and any dead wood. You may find that very sharp scissors are easier to use for these tiny plants than secateurs.
Bush, patio roses, large-flowered hybrid teas, cluster flowered floribundas and standards of these. There are many methods suggested, some of which are very complicated. To simplify matters, what you are aiming for is a cup-shaped bush with well spaced branches, an open centre and plenty of young wood.
First, remove all weak, dead, dying and diseased shoots entirely. Then take out completely all branches growing into the centre or, if two are crossing each other, one should be removed.
Next, shorten all remaining branches back to about 3-5 eyes from the base of the previous season’s wood, cutting to an outward pointing eye as described above.
As the bush gets older, some of the really old and increasingly unproductive branches should be taken right out annually to encourage young ones to be made from near the base.
Weeping standards are pruned like the climbing or rambling varieties from which they have been produced. Some lax growers will weep naturally from the budding union at the top of the stem, ones of stiffer habit may need some training by tying down on to an umbrella framework of plastic-coated metal which is attached to the top of the supporting stake.
Climbers. Prune back flowered shoots to about 4 eyes. Remove old or weak shoots. Tie in new growths when long enough. If you find your climbing roses are growing strongly upright with only a few shoots and the flowers are at the very top and it is convenient to do so, try training the main branches out horizontally. Sub-laterals will be produced from the leaf buds, and these will flower at a lower level.
Ramblers. This is the only group of roses which should be pruned immediately after flowering, removing dead, diseased and old flowered wood and tying in the strong new shoots which will flower the following summer.
Ground-cover roses. Little regular pruning is needed. If they begin to get overcrowded and out of hand, prune as ramblers (i.e. by removing a proportion of the oldest branches).