Fertilize roses in the spring. In order to maintain a high quality bloom, fertilizers should be applied every two weeks from late winter/early spring up until fall. After that, it's not necessary to fertilize or prune the plant anymore. February and March is a good time for watering your roses so they can reestablish themselves after winter dormancy, but there are some exceptions because the rainy season starts in June and rainfall is usually enough to sustain them during warmer weathers so it might be wise to wait for optimal conditions before beginning with soil preparation again. When water levels drop below 50%, which takes its toll on plants too quickly during summer months, you should increase watering frequency at least twice weekly.