I've seen this lots in my garden when digging plants after the summer. It's definitely unsightly, but has never affected the plants. I've sent the plants to others and have felt bad about the way the fans looked, but never heard complaints about the plants' performance.

I guess this isn't helpful in determining what the cause is, but wanted to let you know my experience with it.

Thanks Chris. I've sent pics to Sue B. hoping she can determine what is causing this. I've also got responses from many who say they are seeing similar appearance on the foliage in their garden. I've got 11 clumps dug and cleaned between yesterday and today.
Just a bad day I guess....

Julia

Will you let us know what she says, Julia? I'm curious now. I've seen it before in my plants when I dig at the end of the season. I always assumed it was combined stress from bloom & the heat of summer. Never really gave it a lot of thought though & assumed it was normal.

I'm pretty sure I've seen this before, usually around this time of year--between the end of blooming and new growth. Never thought much about it and never saw any ill effects.
Brad

Nancy: Yes, I'll let you know. Hopefully I'll get some information today. It is very odd that it seems to be coming from the base and spreading upwards. The crowns are fine, just some of the lower foliage and scapes have this discoloration on some of it.

Brad: The plants have done great this year given the hard winter they went through. Just concerned since I've not had this before show up. Too much rain perhaps?

Julia

Mystery solved. It is comes from insect damage. Recommendation is to cut your foliage back and if the plant is not in distress, it will be fine. If your seeing physical issues with the plant then dig it out and separate it out from your other plants if your concerned about it. I was surprised by the amount of folks who reported seeing this at this time of year. I just had the usual dying back of foliage but I guess this year was my year. The job of a gardener is never ending.

This is pretty common for most of my plants in August. I too thought it was normal die back.

Debra

Yes, which is why you haven't gotten Philistine Champion yet. I dug them and potted a couple fans. I figure there's a bit of time, and I plan to lift the clump and see if it is just on the outside fans. It isn't rust or leaf streak. May indeed be another fungus though. A lot of my plants are sending out lovely new UNAFFECTED fans, so I hope it is just weather related from the odd winter.
kay

I have seen what looks the same in south Louisiana in the sugar cane crops down there.It was caused by lots of rain and the ground staying boggy for a extended time. The following year, it seemed to be gone.Dont know if its the same thing or not, but, sure looks like it.I lived in south Louisiana for little over 15 years, next to a sugar cane plantation.

jean

I'm surprised to learn it is insect damage, but then I could never be considered an expert. sounds like it isn't a problem though. Thanks for posting what you learned, this is such a great forum for learning.

Kay: No problem with holding off. It has been a crazy and busy weekend and I'm nowhere near completion and will have to do another round next weekend with the final dig at the end of the month. Hopefully I can complete all the divisions by then.
Still have iris to dig and replant as well.

Jean: We have been getting plenty of rain but we don't get the constant heat that I'm sure they must have in Louisiana. The temps have still been a roller coaster which we usually see in the fall months.