I want to make sure my iris rhizomes are sent successfully. Can any one provide some advice?
What I and many others do for the bearded iris varieties, is dig, trim any excessively long roots, trim the foliage to about 4-6 inches, write right on the foliage itself with black magic marker or maybe a pen while the foliage is dry, wash any soil, weed roots or seeds off of them, check for critters, or disease/decay, and then wrap in newspaper once they have drained and dried a bit. Then ship Priority Mail, as it is not much more than Parcel Post, which no one ever knows how long that may take.
Others may give other slightly different versions of how they handle them...all of which are probably right.
The iris I've received from Schreiner's etc are all prepared just like Sue said & mailed dry (no wet paper towel & plastic here)
and packed with shavings or paper so they don't roll in the pkg via Priority.