The mild winters common to Mediterranean climates means that pruning woody plants in general, and roses in particular, ought to be carried out differently than in cold, temperate climates. This includes both when and how to prune roses bushes.
The reasons for pruning are the same however, irrespective of the climate. These are principally, to induce better flowering in terms of both quantity and quality, and to remove old growth for the purpose of encouraging juvenile growth. The possibility of enjoying the beauty of a rose bush for years to come depends largely on this last point.
When to Prune Roses
In mild winter climates, it is important not to prune too early in the winter, because the combination of warm spells, together with the act of pruning, induces buds to sprout and grow, only for late frosts to wipe out the juvenile tissue. This is not only a source of fungal and bacterial infection, but also is liable to weaken the rose plant in general. As rule of thumb, prune about 6 weeks before the date when frosts are unlikely to occur.
How to Prune Roses
Unlike in cold climates, there is no need to prune the roses hard to the ground. This only wastes valuable energy. Instead, it is often sufficient to remove between a third and a half of the shrub’s height. Preferably, one should cut into young branches, at growing points (buds) that are facing outwards.
New growth does not always develop from old wood, so if all the bush’s main branches are old, it may be necessary to prune higher up the plant, on secondary branches. That is why new growth should be encouraged by clearing old branches at the bud union. (The woody swelling between the roots and the branches)
3 Points to Remember
*While most cultivated rose varieties flower on the current year’s spring growth, some species roses, especially those that originate from continental climates such as in Central Asia, flower on growth that started in the previous spring. The consequence of pruning in the winter, whether at the beginning or at the end, is therefore, to remove all the flower buds. This is invariably the reason behind the common complaint – “my roses never seem to flower!” With such roses, pruning should be delayed until the plants have finished flowering.
*Climbing roses are liable to regress to their non-climbing origins, if branches are shortened too much. Pruning should be restricted to deadheading spent flowers, or entirely removing one or two old limbs.
*Rambling and other species roses are more valuable for their shape, texture, and form, than for their brief period of flowering. Shortening branches, which is suitable for cultivated varieties (hybrid teas, floribundas e.t.c.) spoils the bushes natural shape. In such cases, it is better to thin old wood, by cutting out branches completely.