Leslie, The Keppel Irises I've had have done well here in this extreme weather, so I don't think that if one or two don't work out you need to worry about the others. I had two die of rot last year, they were in that area were I lost a lot of others, and Keith Keppel replaced them both without charge. Same went for one from Superstition, it died, they replaced it. When you pay those prices, they want you to have success.
