I agree with Chanley. My peonies stay wonderfully full and bushy green with a little watering and pruning to get rid of the dead heads until fall.
As for your iris, I leave them alone, too, but take the green stalks, turn the over so the top touches the ground and secure them with a rubber band. They don't look quite so wild that way and it sort of camoflages them as they turn brown, letting the rest of my garden get the attention.
My grandmother, who had a backyard full of bulb-flowering plants, was very partial to iris. She had a ton of them, all different colors. This is what she did to all of her flowering bulb plants after they were finished showing their colors.