Pruning rose bushes in late winter, during their dormancy period, works well for shaping the plants. Light trimming in the summer months, after the bush produces blooms, encourages the rose bush to bloom again later in the season.
Water the soil around the base of the rose bush in the morning, before trimming. Cut off spent blooms at a 45-degree angle, where the stem meets a side branch that bears at least five leaves. Cut the bush back by about one-third to encourage reblooming. Remove suckers at the base of the bush, below the graft, as soon as they appear. If the bush has any branches that are dead, dying or diseased, cut them off at a 45-degree angle, also. Remove and dispose of the clippings to avoid spreading disease or fungal infections.