Pruning Careful pruning can keep roses healthy and help to prevent disease and pest problems. Pruning allows you to remove dead, spindly or diseased plant material, helps to shape plants and promote flowering and new growth, and provides good air circulation to discourage diseases. During the growing season, remove any leaves and shoots affected by disease but do not prune too heavily. The plant will respond with new, succulent growth that is susceptible to aphids and powdery mildew. During January pruning, remove any diseased portions of the plant.
Good sanitation is essential in reducing disease problems.
Remove all diseased prunings and rake up any diseased leaves and blossoms as they fall. Do not compost them unless you have reliably hot compost that you turn regularly. Diseases can be transmitted from stems, leaves, and petals lying on the ground and from diseased plant material. The modern Hybrid Tea Roses and Floribundas only produce flowers on new growth so prune to remove last year s wood. Arching shrub roses should be pruned lightly so their naturally elegant shape is not destroyed.