I alway trim and dispose at the end of October/early November. After a couple hard frosts, the leaves are pretty much dead. Maybe that's why I have never seen an iris borer. (knock on wood)
Looks like Red Handed is going to survive. It had funky blooms this spring, but no increases. Thought it might have had a borer in it since it had a couple v notch cuts in the leaves in the early spring. Dug it up and found nothing. Replanted in an isolated, sunny location and they all seemed to shrivel up. That was until a couple days ago, when I noticed a few new fans coming up. May not bloom next year, but it's growing.
