Iris never need to be cut back in winter, if you can, pull the dead leaves off but leave the greeen leaves. Burying them under mulch will rot the rhiomes although the roots can be planted in mulch. -----Original Message----- From: Kathleen Sayce <ksayce@willapabay.org> To: pbs <pbs@lists.ibiblio.org> Sent: Sun, Nov 25, 2012 11:22 am Subject: [pbs] Iris Colleen wrote about irises and piling leaves on them. It's not clear what kinds of iris you grow, probably tall bearded? Most iris should be cut back in fall or early winter. Then, winter mulch in dry cold climates should not be a problem, unless it gives rodents a foraging advantage. [In wet winter areas, dense mulches like hardwood leaves can create serious fungal problems for irises.] Don't forget to pull the mulch back in spring. Do think about creating a compost area for those leaves and other suitable garden debris. Kathleen Kathleen Sayce PNW Coast, WHZ 8, dryish cool summers & mild wet winters