I sincerely doubt you have harmed them.

The confusing information is, I think, due to different climates and different preferences. The hard frost directions are more revelant than the generic August ones.

In our mild winter (no winter) climate they will grow year round so some people leave the leaves that look healthy. Very different gardening practices than in your zone.

Some people swear by cutting them back. I clean mine up, removing dead leaves etc..but only cut them back when I dig and divide them. I leave the healthy green foliage to help feed the rhizome. You have not killed them. I have seen people here mow them down or take weed eaters to them, They come back, but I have to wonder how that effects the bloom. I do a good clean up in the spring.

You won't hurt your iris by cutting them back now. I had never done any more than clean up the beds either for over 20 years, until I started getting borers. I learned that the moths lay eggs on foliage tips in late summer. In spring, when temps start getting above 50 degrees, they hatch, start down and bore into the leaf and from inside down to the rhizome. Removing and disposing the foliage tips well into the fall will eliminate the eggs, seems to me. Even weeks after I cut mine back, the leaves were already growing back. I don't know what the impact on bloom will be, but I hope far less than the borers, which have severely affected bloom.

Thanks everyone! I'm glad to know I didn't entirely mess up.

I haven't had borers, that I know of, but am glad to think I may have prevented that issue. I'll be interested to see the size of the flowers next year too.