Though summer offers the reward of roses in bloom, it's also a good time to set the stage for next year's flowers. Cutting back rose canes stimulates new growth, helps reduce disease, and improves air circulation, while giving the plant an attractive shape. Although a rose's bloom season varies by climate, a good rule of thumb is to prune shrub and climbing roses after they bloom. (Hybrid teas, on the other hand, should be pruned in early spring and deadheaded regularly.) Rosarian Syl Arena shares some techniques for summer rose pruning in Martha's Turkey Hill Garden.
When working with roses, be sure to wear gloves -- the bushes are full of sharp thorns. Before you begin, evaluate the plants to determine how much work will need to be done. As with any type of pruning, follow the plant's natural pattern of growth. For an overgrown shrub rose like the 'Prosperity' hybrid musk in Martha's garden, Syl recommends removing half of the horizontal side branches to open up the center of the shrub to light and air, and to correct its low-lying habit. Using sharp pruning shears, cut away dead, damaged, or diseased wood, clipping on a 45-degree angle directly at the base of the canes. Remove any stubs, as they will interfere with new growth. Next, decide which of the oldest, biggest canes should be removed. Prune any lateral branches attached to them first, then cut and remove the cane from the base, making sure not to clip off any new growth, such as the young shoots that emerge from the base of the shrub. (Simply cutting at the base and pulling the whole branch out can damage healthy branches you plan to leave intact.)
For climbing roses, such as the large, mature vines on Martha's rose trellis, Syl recommends using the same basic techniques for pruning shrub varieties to eliminate infected, old branches. To train new growth, tie a young, flexible cane (one that emerges from the base of the climber) loosely to the trellis so that it rests in an unforced position. Secure it with a length of natural fiber such as jute, twine, or sisal, looping it several times around the cane. (This ensures that the branches will not rub against the trellis in the wind; the tie will break down after several months if you forget to remove it.) Shorten the secondary branches (those that have sprouted from the long, upright canes) by one-third to one-half. Finish by removing any excess of new uprights, which, if allowed to grow, would congest the long canes that make up the climber's structure.
Arena Rose Co.