I have so much leaf spot. My question: If irises are grown far enough apart will they not spread it? I have one plant growing separately in another garden that doesn't have it, whereas all of the plants planted together in my main iris bed have it. I remember someone here saying that he just ignored his iris bed for most of the summer. I saw a lot of rot starting earlier so I dug those plants and cut out the bad parts but left most of the clump sitting on top of the ground. Then I walked away...Like I said, they are all a waterspotted mess, which only constant removal of spotted leaves through the summer seems to prevent. I can't find the time/energy to constantly maintain my irises so they always look good.
Anyways, I went back to the messy bed yesterday, and found that the ones I had dug and left in a clump had been growing roots all along, so I guess this is a quick stop rot option. There were a few that I dug earlier thinking that I would divide and replant right away, but I never got around to it. Those of course, have not been growing roots so likely they will take longer to become re-established.

Well, I think the more "un-crowded ' bed is, the less disease will affect the plants ,but when we get to the "dewy" time of the year ,you're gonna' get leaf-spot. I spray fungicide, which helps hold it down, but I think I'm going to go back to a "fall burn" plan, also. So, for now, I pull the spent leaves when I have the time and energy, I spray every 10 days, or so, and live with the rest! I try to practice good bed sanitation( un-crowded plants, stay out of the bed when leaves are wet, remove all the "waste' material to the trash, not the compost pile, etc., but it's still there. One trick that I think helps is to spray Miracle Grow on the plants as soon as flowering is done. This seems to cause the "old" leaves to slough off, and a rush of new leaves to start growing. You have just as many leaves to pull, but most of them are at the same time ,vs. being spread out over a 2-3 week period. Also, some cultivars are much more prone to leaf spot than others. I've found the re-bloomers to be much more resistant to both leaf spot and soft rot....Arlyn

Note which ones are the worse for leaf spot & replace them with something else. If it is in the entire bed, you have to take steps like Arlyn does. I had about 6 TBs together, one bloomed & that was the one with leaf spot. It has been discarded.

The one with leaf spot bloomed but the others didn't? Are you saying that they are only prone to leaf spot if they bloom? So let's just get rid of all those bloomin' irises! ;>)

The ones that didn't bloom were not subjected to the extra stress of putting up stalks, and blooms, so probably are much better prepared to withstand the fungus. It expends a LOT of energy to blossom!...Arlyn

All 6 were new last year/ Expect bloom on year old dwarfs, not TBs.