I was going to ask if you had a reference about scorch...but a quick web search turned up a scientific study done by the University of California. Apparently in the right conditions scorch has been found in California. The description is almost identical to what I saw with the exception that the roots were not destroyed. I guess I'm going to have to take extra measures to clean up the field and watch the neighboring plants. Do you have any recommendations based on your experience with scorch?

Here's the link to the study. It's very informative...even if in was done in 1971. Others may find the information helpful too.
http://ucce.ucdavis.edu/files/...

Thanks for the tip Kent. I never would have considered scorch as a possibility.

Here is another article on iris scorch that is even more helpful.

http://eveysblissfulgarden.com...

I hope I'm not overloading you guys...but here is the AIS description of the disease scorch making reference to the first article that I posted.

"SCORCH is a disease of unknown origin that makes an iris extremely sick. Generally the first apparent symptom is the brownish-yellow color of the center leaf in the fan. If this leaf resists being pulled out and the scorched appearance spreads to adjacent leaves, chances are that the plant has scorch. If the scorched plant is dug, the root system will appear to have disintegrated. Scorch occurs most often after mild winters in cold climates. It seems to be the result of stress that occurs when plants grow when they shouldn't.

There are few preventative measures and no known measure is fully certain. In cold climates, mulch to keep the soil around the roots frozen during winter thaws. Time the application of fertilizer so that it is available to the iris during its maximum growth periods rather than when the plant should be dormant.

In a 1971 publication that was not well known, Scorch Disease of Rhizomatous Iris by J. C. Bald implicated the Pseudomonas bacterium which causes scale tip rot of lilies. More recent work did not support the earlier conclusion: Pathogenicity of Pseudomonas gladioli pv. gladioli on Rhizomatous Iris and Its Possible Role in Iris Scorch by A. I. Wrobel, J. E. Watkins, and D. H. Steinegger, 1992. "

And the link to the 1992 study:
http://digitalcommons.unl.edu/...

Marilyn.. Take pictures if something pops up that looks similar to it again the center leaf of the plant is what you want to pay attention to.The tell tale sign for me was the middle leaf would turn brown and die and the plant with a gentle tug would come out of the ground with shriveled roots which is something that should never happen with a healthy plant, if you have scorch it has a obvious look to it but starts with the middle leaf.

I had a battle with it 3 or 4 years ago when we had a really unusual warm winter our thought process at the time was it was being spread through the Leaf hoppers, it does not spread through the soil like soft rot would it needs a host and we are convinced it came from the bugs chewing on the foliage. I never found a cure for it the way I got it stopped was digging every plant that had it and disposing of them or risk it spreading to others.I also sprayed for leafhoppers weekly to kill them, I would be surprised if this is your problem it is rare in Iowa but even rarer where you live if the roots are not shriveled and center leaf not brown it is something else which is a good thing you don't want that monster in your garden although for me Botrytis is more devastating and will likely be a yearly battle until I figure out a way to kill it or prevent it and will take a long time to try different fungicides on it and how harsh the winters here are.

I had a thread a few years ago with pictures on it showing exactly what it looks like at the time had no idea what it was or what was going on there still is very little info on it out there.

Moiris said: Do you have any recommendations based on your experience with scorch?


Thanks for the tip Kent. I never would have considered scorch as a possibility.

I had a small outbreak of what may have been scorch in my garden in 2013. Lost 'Dancing Star' and 'Jazz Era'. Part of a clump of 'Beauty Becomes Her' showed symptoms as well, but I dug out the sick-looking fans and the remainder of the clump seems fine (knock on wood). None of my irises showed signs of it last year.

Beyond that, I really don't know anything about scorch, if that's even what it was, except I hope to never see it again.

I'm going to take a closer look at the roots tomorrow. All of the other symptoms are textbook symptoms of scorch, so either I found them in time to prevent root damage (unlikely) or I overlooked some early signs of damage. I will also take a closer look at the surrounding iris clumps.

The rhizomes were securely anchored by their roots, I had to dig them out. But other than that all the symptoms were there. The leaves started dying at the tips (but I didn't look close enough to notice that it was the new inner leaves that were dying first), the dead leaves would not pull off, when the outer leaves were removed from surrounding healthy-appearing rhizomes the inner leaves were a sickly yellow green and were limp, the rhizomes were firm, the dead leaves were a reddish brown and looked like they had been burnt. The problem occurred in the bed that had the scale problem late last summer...so it's possible the scale were the vector for the infection.

Since one of the studies said that rhizomes left out in the sun (we are having warm weather) for a long time can be cured...although when replanted in fall they probably won't bloom for a year...I'm thinking I might try to 'bake' a few on the patio for the sake of science. If I decide to try this I will keep them separated from my other plants. I'm not sure I want to risk it though...

"baking" them will help....I have saved a few that way. I have heard that people have also "solarized" (covered with plastic) the soil where the iris were grown, to sterilize it before it was replanted...but I never did it.

They call it the 'blacktop bake' here for scortch. They dig the iris and remove the dirt and lay the rhizome on the blacktop in the direct sun for a week and then replant. It seems to do the trick but our blacktop areas here get hot enough to cook an egg easily. I have never had scortch or borers but I had the beetles that ate the roots last summer. The iris in the parts of they garden where the beetles were living just seemed to stop growing and then just to look a bit dried up. I dug some up and found black beetles living in the roots and eating them. Once I killed the beetles the iris rebounded but the fall bloomers did not bloom last fall. They had to recover from being gnawed on all summer. I have already treated for the beetles this year even though I have not seen any. I am watching for any signs of them. I'll teach them to eat my irises!

I read all of this, and wonder again why iris are listed as carefree flowers that require a minimum of care!

I think it is because some survive no matter what you do to them. Two years ago I bought some different varieties from an iris sale and when planting them little unmarked increases had come loose and were in the bottom of the sack. I put them in a plastic flower pot and was going to plant them later in the NoID garden. Two weeks ago I was attempting to do some clearing of clutter on the garden shed shelves and ran across the pot of little rhizomes. They are sprouting. If there were plant police I would be arrested.

I had one cultivar two years ago that looked like it had scorch. I dug it up and discarded it. I replanted a new iris in the same spot later that summer. The new iris has done well. I had no others like it, so if it was that, I think I got it in time to keep it from spreading by insects to other plants. They seem to think it needs an alternate host to spread.

I had one last year with a bad case of rot. I dug it up, cut out the bad rhizomes, soaked it in bleach water, and left it dry out for a few weeks, then replanted it in the same spot without treating the soil. It grew back, and it seems good this spring. Nothing near it was affected.

They sure were patient little increases. You are safe from the plant police as long as they are treated better from now on!

grannysgarden said: If there were plant police I would be arrested.

tveguy3 said:
I had one last year with a bad case of rot. I dug it up, cut out the bad rhizomes, soaked it in bleach water, and left it dry out for a few weeks, then replanted it in the same spot without treating the soil. It grew back, and it seems good this spring. Nothing near it was affected.

When Secret Rites got rot, I did the same thing as you describe. The surrounding iris never were affected. Secret Rites is rot free, but just not increasing in the old site. Think this is more an issue with the plant itself.

Looks like I'm losing 'Queen's Circle' and 'Quite the Same'.. their methods of demise look different... 'Quite the Same' is clearly rotting and 'Queens Circle' feels like it never rooted, and the leaves are turning yellow. Either way... not happy. QtS is variegated, and I sort of have a thing about variegation...

If you want to try Queen's Circle again I should have plenty to share Sherry.

I dug away some dirt where Owyhee was planted then soaked the hole with a bucket of diluted bleach.

I hate losing plants...

Lestv said:
I read all of this, and wonder again why iris are listed as carefree flowers that require a minimum of care!

They are easy to grow and easy to kill.

Put me down for one, Marilyn... and thank-you! It was one I was looking forward to.

Well, after another 'look-see" at the beds, and a few more days of "greening up", it looks like my losses are about 38 plants . There are 11 of them that "may" pull through, but it will be 'iffy" .18 of them were "first year", planted just last summer, and the rest were 'older' plantings. I'm doing pretty well finding replacements, but there are a few, that, I'm afraid just won't get replaced very soon....just too darn scarce !

So sorry to hear that, Arlyn.