So Gordon, I noticed how terrific your rhizomes and fans look, and I know that you live in the Tucson area, and I'm just wondering what month(s) you do you your dividing in? I live in Bakersfield, and I've really had a problem with our hot summers, especially in this one bed (where I keep my new introductions, of course!) that is flat rather than on a slope. I plant my rhizomes a little deeper because of our heat, and for the last two summers I have used mulch in that bed to keep them from cremating, although I try to keep the mulch from actually touching the rhizomes. And they don't even get a full day of sun! I never would have tried the mulch except that a friend I gave rhizomes to used it around hers and her iris were absolutely beautiful and not burned -- and no soft rot!
I even pot up all my new ones I purchase each year and keep them under my slatted pergola and don't plant them in the ground until October, and this really helps because they root in the potting soil so they've already been growing by the time I finally get them planted, and they haven't been stressed.
But your plants look totally fantastic like they'd been grown in another part of the country rather than in a hot, dry climate! I want to know your secret!!!
My secret, I don't have one secret. I built raised beds and filled them with very well drained soil with alot of compost mixed in. I fertilize more than they recommend and water all summer. We have monsoon rains in the summer, which brings the temps down and brings in alot of cloud cover. I try to do my dividing when we have at least a week of forecasts in the low 90's. If that doesn't happen, I wait until October. Part of it is the new soil. I don't think they'er doing as well this year. We have had the coldest lows in history. We got down to 15, and last night we had snow.
Well, they sure do look terrific! Wish mine looked that good -- but I guess I'll just be thankful they're still alive by September each year! I water all summer, too, and I heard they need 1/2" of water per week to stay green. And mine really do try to stay green!
I think I need to beef up my soil next. They do usually look good by the time they bloom, at least...
The soil around here is like adobe clay, more like cement. I actually had to buy a jack-hammer and dig below the clay to get proper drainage. In some spots, I had to dig down 2 feet and just discard the clay.
Oh man, that sounds awful -- like my sister's clay soil out by the mouth of the Kern Canyon! She elected to have several inches of top soil put on rather than try to dig through it, other than for tree planting. I really don't know how you do it! And your raised beds really look fantastic!