Hello Colleen, > I have an unexpected large amount of [elm] leaves this fall, > ...so I have been piling them on my flower beds as a mulch. > Most of my Iris still have green leaves. Is it OK to bury > them under leaves? In your desert climate you might get away with it if you don't give extra water all winter. (I bet you don't do that.) Are you thinking of mulching the Iris beds because of other things in there? The Iris don't need the mulch and are prone to rot if too wet. Leo Martin Phoenix Arizona USA