As long as none of the mulch covers the top of the rhizome, it is fine. I have trouble keeping the mulch from migrating, though. It's as though that one little two-inch square patch of unmulched iris top is an affront to the mulch, and it must find a way to cover it up.

What did you buy?

Renee

We bought 6 rebloomers. I have some that rebloom so had to have more. Mariposa Skies, Cantina, Harvest of Memories, Autums Circus, Clarence and Jennifer Rebecca. The other beards are Fall Fiesta,Spirit Mountain,Ghost Train,Feel Good,Blue Skirt Waltz,Early Girl,Devil's Riot, Lightshine,Monet's Blue, Autumn Circus, Rhinelander,Fade to Black,American Classic,Autumn Riesling, Play with Fire,No Count Blues and Pallida Albo Variegato(purchased later). I have one of these and really love the foilage so had to have another. Forget if it's bearded or not.
I'm sure someone said this before but Iris are like potato chips, you just can't have one. LOL But they are a harmless and lovely addiction/addition for gardeners. My husband worked like a dog getting the site ready. I helped but the heavy work of rototilling and moving rocks was his job. The soil is composted, rich and well drained so fingers crossed they will be happy and not get an attitude. SIGH!

No mulch. A lot of people locally use Preen.

What a lot of work you have done. Oh, I hope you post photos next year. It sounds glorious!