I'm sorry I don't have an answer for you Sissy. One site I found said to give new plants plenty of water. Then I found this:"Plants must have excellent drainage, particularly in hot, humid summer regions or areas with wet winters." I'd say you have both those summer and winter conditions.My regular iris are starting to brown on the tips, I think from lack of water. I've found Iris to be tough plants, I bet it makes it.
Heck if i know Sissy . . . maybe the soil isn't rich enough???Keep us posted.
Sissy, it could be that you've got iris borer, but it could also be from moisture. I've always got a few iris that do this same thing and they always manage to come back in the spring, so don't give up yet!
Sissy,It may be too late for this, bvut I agree with kylee. I would take it out and check for a borer and water. I've noticed that my irises don't like to be "extra" watered and if they ever look like this I remove what's bad and replant. Good luck!
I would love to hear from you and if you can leave a comment, I will visit your blog, too!