Bonnie and Arlyn suggested starting a thread to list your sturdiest Iris that flourish in the harshest conditions. Harsh for some of us means extreme cold; for others of us, it means extreme heat and dryness.
Having just gotten started with named Iris, I only have established history the two that were here when I bought the house. Can't tell you the name of them, but they stand up to anything a North Central Texas weather year can throw at them.
