The reason she does this is to reduce the leaf spot diseases that are common in Iris. If the leaves are healthy wait as long as possible to do this as they are still feeding the corms. There is an Iris forum which has more than I can tell you, and probably more than you will ever want to know about Iris.

Thanks,thought about specific Iris forum after I posted here,but wanted to hear what my local GWers do.

Thanks for that great summary of iris care, WG.

I think Ajax - or maybe Bon Ami, which doesn't contain anything but an abrasive, is perfectly acceptable to organic gardeners. It presumably kills by cutting the soft-bodied stage of the borer. I used it (Bon Ami) when I had an annoying ant problem in a brick landing, at the base of outside steps.

Ditto everything white garden said.

I've usually found that 4th of July is about the right time to divide the rhizomes. My irises tend to bloom in late May and early June - so it is late June by the time all the blooms have died off and the stalks are starting to die off.

I've also found that I tend to divide the irises every 3 years.

I use a grub killer with imidacloprid on my irises - which has been effective in killing the iris borer. 1 tsp per rhizome applied in the spring. Imidacloprid does not kill earthworms.

Irises do like well drained soil. I'm making a new bed by my pond for my irises - instead of just adding lots of compost to the bed, I'm also mixing a lot of sand into the bed - to assure good drainage.

Wow, diggin, that's good to know. I will stick with the powder then since it has been very effective in the past.

I've understood the reason to use cleanser on iris is that is often contains bleach, and bleach is a recognized way of dealing with the various rots the occur on iris that have been damaged. It's not to kill insects.

The alternative is to dig up the iris, then soak them in a bleach solution and replant.

hmmmm . . . I've never bleached my iris rhizomes.

Okay, this post I'll save and refer to next spring. Great information on care for my clumps of iris, that I've also been neglecting.

Molie

Hey whitegarden et al--thanks for the info. So it sounds like now,the fall, I don't do anything? Should I even cut the leaves down to 6 inches or shorter? Thanks

Whitegarden,

That was a great post on Iris care. I've saved it to my "clippings" file. I did some additional reading on Iris borer and found that certain types of beneficial nematodes will control Iris borer at 100%. Have you ever used those?

Here's a link (under Iris basics, borer control)

Steve

Here is a link that might be useful: Iris Societies

Thanks steve, I'll check that out.

The only thing I would do now is check your planting depth and check if any of the rhizomes are soft. Just push on them at the top near the fan with your finger. If they have soft spots, you shoud probably lift them up and cut out any of the rotted areas now and pop them back in the ground. I only cut back the foliage if I have lifted them, but it won't hurt anything to do it now. The foliage will die back over the winter and have to be cleaned away come spring anyway.

I'm afraid I missed all this spring and July activity. I had a beautiful iris garden in California, made up of mostly rhizomes I had transferred from my late mother's house to my new digs on a ranch in a dry canyon. The rancher transferred my iris to her garden at the big ranchhouse after I moved and promised to send me rhizomes. Well, she did -- I received a box with what looks like 30 or 40 of all sizes. I'm ecstatic to have my mother's flowers again. Trouble is, it's November. What is the best way for me to handle them?

Here is a link that might be useful: Canyon Communique

SilverBee - first of all, you are in Tennessee, so your timing may vary a bit from our timing here in New England. You can still follow the directions given by WhiteGarden, but just vary your timing depending on when your plants bloom.

As for the box of rhizomes you just received, I would just plant them in the ground now. They may not bloom next spring, but they will have next year to establish and you should get beautiful blooms the following year.

Some of the replies here are seriously overcomplicating the situation. Iris need to be thinned out when they have multiplied to the point that there is no empty space between the rhizomes. It's a simple as that. Just clip of the tops (some people use a lawn mower), dig them up, put about a third of them back with a few inches in between them and plant them so that the top half of the rhizome is above the soil. I've never used any sort of fungicide on them at all.

OK tree oracle--I'm with you. I must have planted them at the right depth to begin with since they bloom beautifully. I added a few new rhizomes that friends have given me to this bed and it just looks nice and tidy so far. Thanks,jardinista