I think what you do depends a lot on where you live. I let the leaves stay where they fall among the irises. I leave the green leaves on the irises. My reason is that it will trap the snow some and it helps keep the ground covered with snow. I have the biggest problem with rot in areas where the snow blows away or melts on and off during the winter. When the snow cover stays constant I seem to have less problems. My friend in town who has irises cuts hers back every fall, and still gets good bloom. I think irises really survive in spite of what we do more then because of what we do.
It's important to get the leaves off though very early in the spring.
