The leaves have tiny holes in them. Is something eating them? What can I do?
What Is Wrong With My Knockout Roses?
The tiny holes are likely caused by some small beetles that poke holes in the leaves to such out juices for their survival. Spraying the roses with a good insecticide should take care of the problem, use the least harsh insecticide first, like a Safer brand and move up if need be. The holes will not disappear but should stop being present.