I never use to use mulch anywhere but in my hosta beds, but I am now using it in everything. I just make sure that I leave a circle around my peonies and I plant my iris on a mound and then mulch up to the mound. As far as digging out a bed, I don't dig out anything. I just spray the area that I want a new bed in with Round-up and kill off the grass and then I skim the sod off the areas I want to plant in and mulch the heck out of things. ;) If I can't wait for the round-up to kill things off, then I skip it and just mow the area really close and then skim the sod off where I want to plant and then lay down newspaper sections and or cardboard and mulch away..
Both ways work just fine. Thus, no digging! Yay!!
