We are lucky to not have iris bore here. I have seen leaf spot on a couple of varieties....I discarded them. I forgot to mention that my soil is clay but drains well. I think I have mentioned this on cubits but I had a friend here who grew over 400 varieties. He grew them in rows with a furrow on each side. He irrigated weekly. Each fall-summer he would put his lawn clippings in the paths and in the fall would put aged cow manure down each path and then till it in. Next year right after bloom he would move the iris into the paths and the process would begin again.He moved them every year and had great bloom and great rhizomes. After many years they weren't doing as well and he had a soil test done and found his soil was high in animal salts from the manure so discontinued using it.
