Thank you very much for information. I read it. I have attached the picture to the question, but I don’t see it. Something I did not get about uploading image. OK, I will figure it out. Only looking on the picture I found out what might be the cause of a fungus (I am not sure). What do you think, can the very old rotten fence be the trouble maker? The irises are growing right next to that fence. Over there are several other plants, such as phloxes and clematis, they don't look very good also.
