Hi Cinda!
I am having problems with iris borers this year also. As I clean out each infested area, I am looking through the loose soil for the little brown pupae forms of the borer. When I find them they get put out on the driveway for the birds to eat ( along with any remaining iris borers that I find - nasty things!)
Healthy, cleaned rhizomes can be replanted in the same area. In the spring I will treat the area with a heavy dose of grub control and hope to NOT see any borers next year.
Good luck with your reclamation project!
