GAAAAHHHHH! After one day of rain, I went out to check my iris and several are mushy and starting to rot on top. I could understand if the rot was on the bottom or where the rhizome touched the ground, but why on top? What causes this and what do I do about it?

I noticed that most of the rot started on the tops of my Iris as well. I would guess that it's where the spores find easy entry. Were these new Iris, or an established bed?

I think that rain, dew, .....whatever....collects in the "leaf folds", where they attach to the rhizome, and that's where the "top" rot starts.

I would think that's often the case too. Although I was thinking that it could possibly be due to an injury to the rhizome as well. Some of the rot I cleaned off this year was not around the base of the fan, but on old leaf scars further down. That was identified as probably Mustard Seed fungus and may present itself differently than the more common crown rot. I haven't had as much experience with rot as some of you, so I'll leave it to those who know more.

My rot was further down on the rhizome too. I didn't see any damage to the rhizomes, just all of a sudden noticed they were getting mushy. I didn't notice a smell, either. My friend suggested cutting out/off the mushy parts then soaking them for 30 minutes in a 10 percent bleach solution, so I did that. Then set them out to let the cuts scab over and wouldn't you know, the rain started again. Sheesh! Do you need to do something special for Mustard Seed Fungus? These were in a new raised bed that I used all Kellogg's raised bed mix in. There wasn't any moisture against the rhizome.

I don't know much about mustard seed fungus, except that you'll find kind of a cottony substance in the folds of the leaves, followed by spherical fruiting body that resembles mustard seed.
http://www.ipm.ucdavis.edu/PMG...
http://www.irises.org/About_Ir...

There's a good picture of the fruiting structure and white moldy growth on a peanut stem.
http://ipm.ncsu.edu/peanuts/di...

I was told to scrape out the soft part until you get to healthy tissue, then soak in a ten percent bleach solution. Swish it around so that you get in the leaves, and I pulled the leaves apart a bit to make sure the bleach solution got in there. Then dry for a day or two before replanting. It was recommended that I replace the soil where it was growing as well. I'd say that's pretty much the advice for other fungal rots as well.

After Hurricane Joaquin blew by I had to toss a few small rhizome transplants

Being another Carolinian, I know how that goes!

Hey Cuzz! Welcome to our little corner of ATP!

From California.

Welcome Cuzz4short from California.

Greetings Cuzz4short. Hope you did not lose too many plants in that weather event.

from New England

Yup. I planted a new bed with Schreiners "Armload" collection in late August. About 5 days later we had a pretty hard rain. Another 4 days and another rain. Lost about 20% due to rot! The center fan falls over and leaves the trademark "mush". Thank you Schreiners for your replacement policy. What I finally ended up doing is cutting most of the rhizome away from the small increases and carefully dug out the main rhizome. The small fans seem to be doing OK, we'll see if they survive the winter.

Greetings John, and welcome to the iris forum!! It sounds like you may have saved a lot of your irises with early treatment. I have lost only a few this summer, probably due to lack of rain. I hope I make it through the winter without any rot and enough moisture to inspire spring bloom.

I don't remember ever having rot on a newly planted iris, only those who made it through the winter, and then got rot. I've had a few that just didn't take root and die though.

This year Grace Upon Grace turned to total mush within 5 days of planting. Boy that made me sad. And Kid Clothes did the same thing, only it had been planted about 2 months. I think it is the very wet summer that is doing mine in.

Yup, in about 5 days. Lost an entire row.

Mind telling me where you got Kids Clothes?

Out of the several I had planted I only lost 5 or 6 small transplants during the hurricane system. It was heartbreaking honestly. All plant lives matter, especially the smaller ones