If you remove the existing roses the plant will know it hasn't successfully produced fruit and will try again with new blooms. Normally you can just catch the dying flower and snap it off, but if you've got an infestation and you want to take off more, you can cut back to just above some mature leaves. Cut at a slant so rain will run off the cut edge, rather than pool on it.We had lovely huge roses fro the last few weeks but now some insects have gotten to them. If I spray something on them now will they grow again before the end of the summer? Why cant they just look after themselves? Useless show off bastard things.