Most roses should be pruned toward the end of their dormant season when the leaf buds begin to swell. However, roses that bloom on old wood should not be pruned until after they flower. Some gardeners use the blooming of the forsythia plant as an indicator for pruning roses.
Modern ever-blooming floribunda, hybrid tea and grandiflora roses bloom once per season on new wood. These roses respond well to trimming at the end of the dormant season. However, ramblers bloom once on old wood. Owners should limit pruning of these roses to remove any dead wood or winter damage as the dormant season ends, but major pruning should take place after they bloom.
Modern shrub roses bloom on mature stems but not those that have become woody. Leaving them untrimmed for two years after planting increases their vigor. Once they are established, owners should remove approximately one-third of the old stems each year along with any stems that are damaged or diseased.
Some climbing roses repeat bloom. During the early growth season, they benefit from pruning to remove damaged and dead stems. Once they finish blooming, trimming ensures the bushes remain a manageable size.
When trimming roses, the tools should be sharp and clean. Pruning helps to increase air circulation and prevent diseases while shaping the bush. Cuts should be made at 45 degrees just above a bud that faces out from the center of the plant.