Hi English
I do not mulch our tall bearded at all, as it can cause rot. We keep it worked up and as weed free as possible.
As for the other areas, mulch is great...and very little weeds.. HAPPY IRISING

I do not mulch my iris beds either, hand weeding is the only thing I do. One yr I tried Preen and it cut down on the amount of weeds, but not enough for me to use every year.

littlebit

I NEVER mulch my iris beds! They don't get much in the way of weeds, because I keep them dry, and in Nevada, that means very nearly "Incapable of supporting plant life, especially weeds". I pull the few weeds that appear. Okay, so I do let the leaves that fall in autumn from several trees stay put, but that's because I'm lazy. It's so dry here rot simply isn't an issue unless I try and plant bearded iris in a pond.

I do mulch around the irises, and it does help with weed suppression in early spring. The irises are so interplanted with other plants there is little room for weeds after things are up and going in late spring. I hand pull the johnny-jump-ups and the like that self seed into the middle of a clump, but otherwise there's just no where for a weed to grow in the beds by early summer. In spring I wait until the weeds sprout then mulch so the seedlings suffocate and die, otherwise the seeds just sit until they hit the surface again and then sprout.

In my small garden this is relatively easy though. It won't be feasible for everyone. And the downside is I am constantly battling leafspot because of no air circulation between the plants.

Mike

Yes; as damp as it gets here in Michigan, in June it is generally pretty dry and my soil is quite sandy, so even the iris will be unhappy if I don't mulch the beds and the weeds will be rampant. However, I don't mulch much close to the TB iris; they are in with the other perennials and lilies and those other guys really need the mulch.

I tossed some extra rhizomes on a grass pile about 3' high that was suppressing weeds on a former vegetable garden. I figured they'd either rot or dry out but eventually I'd get compost. Hah! Those are some of my healthiest iris.

I don't put mulch right up on the rhizome anymore, this can cause rot. I think they like it drier than the mulch allows. I learned the hard way last year. Thought I was doing good to mulch, but it caused them to get a bad cause case of mold. Now I keep the mulch pushed back away from the rhizome.

I have always been an anti mulch person, so it is a surprise to me that those bearded irises that were mulched (not over the rhizome) last year, have done incredibly well.
They have been mulched with pea straw, and I find I have to constantly drag it back because the blackbirds spread it over the plants. Even just a light layer of peastraw keeps the weeds under control.
Of course there are cases of rot where the mulch has got too close to the rhizomes. The growth and increase on most have made up for any lost to rot.
As I get older and find it more arduous to get round the garden to weed everything, on my acre of land, i think I will be using more and more pea straw on my irises, and culling anything that objects to it :-)

I mulch with pine straw, only in the winter.