By Gattina
Bologna,
Italy 
Bearded irises do very well in our area, and look glorious in early summer. I have successfully divided plants in the past, and remembered to replant with the rhizome partially above the surface of the soil; however, we have very harsh winters up here in the mountains, with sometimes months of snow cover, and I'm not entirely sure how to proceed. Different websites say "mulch for protection" or "don't mulch, it'll rot the rhizomes." and some say "cut back hard", others, "just remove dead leaves". I'm confused! Any advice would be very welcome.
26 Sep, 2015
Answers
I've been growing irises here in New York forever. We have back to back blizzards and temperature fluctuations all winter. They grow like gangbusters. They are extremely hardy and robust plants given a few requirements which you are providing. Remove all dead foliage when it goes dormant. Keep their area clean and tidy. Keep them in a well drained area, don't let them sit in water or muck. I don't mulch them - they like to be partially exposed to the sun and air. Mulch would compromise this purpose.
26 Sep, 2015
Growers in Flagstaff, AZ don't mulch them, and they have quite harsh winters also.
27 Sep, 2015
Thank you, everyone. Very useful stuff!
27 Sep, 2015
I never mulch mine and they came through those 2 horrendous winters.
27 Sep, 2015
Actually, I've been weeding and generally tidying the border where they are, and have been back today to brush off soil the rhizomes, so firm is the message not to cover them. I'll mulch everything else, though, I think.
27 Sep, 2015
PM Siris - she knows heaps about irises.
26 Sep, 2015