I'm having a hard time wrapping my head around using peat moss. Any kind of fine bark and anything else well draining, I guess.
I pretty much use the same potting mixture for both irises and daylilies, unless I am in a hurry, in which case plants go into whatever "recycled" dirt from pots I am no longer using. Judging by the results in my raised daylily seedling beds (originally filled with fresh 10% vermiculite and the rest 50/50 planting mix and fine bark), the bark breaks down fairly quickly (within 2 years), adding organic material to the mix. Generally at the 2 year mark I need to dig and beef up the beds again, so it's back to the original mixture to replace any lost soil volume.
