All good advice Chris.
If you are moving entire clumps you can move them almost any time after they are scheduled to bloom; just use a spading fork and lift the entire clump and place in the new hole but press in the dirt around the roots and keep the rhizomes at the surface. I then take the excess dirt from the new hole and place it into the old one. Amending with compost is a big help, and use a basic fertilizer once a year in the spring, but not with high nitrogen like that for sod. Water them in maybe 3 times a week for two weeks or so to get roots started and air pockets filled with soil. Clay can grow irises! I place "raw" compost between the rows/clumps; the roots grow into it as it decomposes.
Good luck with them; you should see improvement even by next season.
