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Jul 22, 2014 9:42 AM CST
Thread OP
Name: Geof
NW Wisconsin (Zone 4b)
Dahlias Region: Wisconsin Celebrating Gardening: 2015 Garden Ideas: Level 1
I know this is a really basic question, and I did try to search for it using the "search"

I have a lot of old fashioned noid yellow iris, They were here when I bought my house, planted in an area to shady for them to bloom. I have moved and divided them several times over the past 10 years, and they are beautiful until mid-late July.

The foliage then starts yellowing and dying back, and generally looks terrible. It takes a lot of time to cut leaves back individually as they get ugly. At this point in the season can I just cut them all back to 3-4" tall? Have they had enough time to store up nutrients for the winter?

Thanks for the help
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Jul 22, 2014 10:18 AM CST
South central PA (Zone 6a)
Irises Region: Pennsylvania
Based on all of my known science and lore there are two times for cutting foliage: when it looks bad and browns, for aesthetic reasons, and also in the early/late fall if desired for same reason.
Story is that Schreiner's in their early days cut foliage for shipping and it spread to others thinking it had to be cut in July/August, but it does not. Just getting out "spent" foliage is usually sufficient.
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Jul 22, 2014 10:40 AM CST
Name: Tom
Southern Wisconsin (Zone 5b)
Butterflies Vegetable Grower Keeper of Poultry Irises Keeps Horses Dog Lover
Daylilies Cat Lover Region: Wisconsin Celebrating Gardening: 2015
A lot of people do cut it back in the late fall though, and it doesn't seem to hurt anything. Some burn it off in the spring, if they are away from things and fire won't hurt anything else. The main reason for getting rid of the old leaves in the spring is to help reduce the iris borer population. In the other seasons getting rid of the dead leaves helps reduce the moisture around the rhizomes to help reduce the problems with rot. One of my friends cuts it back every fall, and I usually don't. We both have good results.
Politicians are like diapers, they need to be changed often, and for the same reason.
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Jul 22, 2014 2:11 PM CST
Name: Lucy
Tri Cities, WA (Zone 6b)
irises
Charter ATP Member Cottage Gardener Irises Region: Northeast US Region: United Kingdom Region: United States of America
Enjoys or suffers cold winters
We cut back Siberian foliage in the fall & just trim the bearded irises which are brown. The foliage helps the plants make food for the following year.
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Jul 22, 2014 4:51 PM CST
South central PA (Zone 6a)
Irises Region: Pennsylvania
Instead of cutting back the foliage in the fall I just make sure the fallen leaves don't pile up on the clumps which can allow overwintering of undesirable critters and of course remove the foliage that has died off for the same reason. Even doing this I do get the occasional undesirable borer. The back end of one is shown here.

Thumb of 2014-07-22/DaveinPA/3d70f2
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Jul 22, 2014 5:12 PM CST
Name: Bonnie Sojourner
Harris Brake Lake, Arkansas (Zone 7a)
Magnolia zone
Region: United States of America Region: Arkansas Master Gardener: Arkansas Irises Plant and/or Seed Trader Moon Gardener
Garden Ideas: Master Level Dragonflies Bulbs Garden Art Celebrating Gardening: 2015 Gardens in Buckets
How do you find borers in an iris rhizome? Do you have to cut it open or can you see from the outside if there is a borer in there?
Thro' all the tumult and the strife I hear the music ringing; It finds an echo in my soul— How can I keep from singing?
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Jul 22, 2014 6:11 PM CST
Name: Tom
Southern Wisconsin (Zone 5b)
Butterflies Vegetable Grower Keeper of Poultry Irises Keeps Horses Dog Lover
Daylilies Cat Lover Region: Wisconsin Celebrating Gardening: 2015
Sometimes you can see the damage on the leaves, but other times they go right through the center of the leaves to the rhizome and you can't see it 'till you dig them.
Politicians are like diapers, they need to be changed often, and for the same reason.
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Jul 22, 2014 6:32 PM CST
South central PA (Zone 6a)
Irises Region: Pennsylvania
Tom is right, they sometimes leave chewed leaf edges. Also look for frass near the base. In my case the chewed leaves gave it away as frass was only inside the leaf fan. Another clue can be an outside leaf that falls over and is soft on the bottom, but this is also a clue to bacterial rhizome rot as well.

When discovered I removed that particular rhizome, trimmed leaves, started cutting into the rhizome following the path of the borer. Once removed, with damage to its "face" since it did not want to come out, I treated the rhizome with chlorine cleanser powder and replanted it but with no watering in until the cut area was able to skin over for a day or so to reduce chances of bacterial rot. If there are lots of the infested variety I just toss the rhizome.

Thumb of 2014-07-23/DaveinPA/0ebdb4 About 3 cm., just over an inch.
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Jul 22, 2014 6:54 PM CST
Name: Bonnie Sojourner
Harris Brake Lake, Arkansas (Zone 7a)
Magnolia zone
Region: United States of America Region: Arkansas Master Gardener: Arkansas Irises Plant and/or Seed Trader Moon Gardener
Garden Ideas: Master Level Dragonflies Bulbs Garden Art Celebrating Gardening: 2015 Gardens in Buckets
Gross!
Thro' all the tumult and the strife I hear the music ringing; It finds an echo in my soul— How can I keep from singing?
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Jul 22, 2014 7:23 PM CST
(Zone 9b)
Region: California Garden Ideas: Level 1
Yummy? Blinking

That is one nasty, ugly looking pest! Do they at least make good fishing bait?
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Jul 22, 2014 7:50 PM CST
Name: Mary Ann
Western Kentucky (Zone 7a)
Bee Lover Irises Hummingbirder Hostas Keeps Horses Farmer
Daylilies I was one of the first 300 contributors to the plant database! Container Gardener Cat Lover Region: Kentucky Birds
Gross..................
Thoughts become things -- choose the good ones. (www.tut.com)
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Jul 22, 2014 8:21 PM CST
South central PA (Zone 6a)
Irises Region: Pennsylvania
Good for bait, but costs you time and energy in extracting them from the rhizomes! Then the "gross" thing is traded for a delicious fresh fish dinner. That is a pretty good trade.
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Jul 23, 2014 9:44 AM CST
Thread OP
Name: Geof
NW Wisconsin (Zone 4b)
Dahlias Region: Wisconsin Celebrating Gardening: 2015 Garden Ideas: Level 1
Thanks - the thread got a bit hijacked, but I learned about borers.

I will cut them all back.
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Jul 23, 2014 10:28 AM CST
Name: Leslie
Durham, NC (Zone 8a)
Garden Photography Cat Lover Irises Region: North Carolina Peonies Enjoys or suffers hot summers
Celebrating Gardening: 2015
Not truly hijacked like our forum threads are apt to be Whistling in that borers are related to foliage. Borers lay eggs on the leaves, that then hatch and crawl down the inside of the leaves and down into the rhizomes. To get rid of the eggs is why many people cut back the foliage in the fall. I want my iris to grow as much as possible during the summer & fall so I keep my leaves until October or so, then cut them back. It gets really wet here in late fall so if I don't have a clean garden then the rhizomes are open to rot.
"The chimera is a one time happenstance event where the plant has a senior moment and forgets what it is doing." - Paul Black
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Jul 23, 2014 1:01 PM CST
Name: Bonnie Sojourner
Harris Brake Lake, Arkansas (Zone 7a)
Magnolia zone
Region: United States of America Region: Arkansas Master Gardener: Arkansas Irises Plant and/or Seed Trader Moon Gardener
Garden Ideas: Master Level Dragonflies Bulbs Garden Art Celebrating Gardening: 2015 Gardens in Buckets
I never cut my foliage. I pull the dead outer leaves off but never cut into a green leaf. I am not bothered by rot and I have never seen a borer, knock on wood, and hope I never do. I have friends who cut their leaves off when the tops brown a bit so their garden will not look unkempt. I just water during a drought and the leaves seem to be o.k. If our water table keeps getting lower watering habits may change.
Thro' all the tumult and the strife I hear the music ringing; It finds an echo in my soul— How can I keep from singing?
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Jul 23, 2014 2:18 PM CST
Thread OP
Name: Geof
NW Wisconsin (Zone 4b)
Dahlias Region: Wisconsin Celebrating Gardening: 2015 Garden Ideas: Level 1
I just did a google search and I believe what I have is Iris Leaf Spot http://www.extension.umn.edu/g...

I have not cut off the dead/diseased leaves in the past couple of years, and we have had an incredibly rainy spring. That explains why it seems worse this year. I am definitely going to cut them all back.

Thanks all for your input.
Avatar for Mbl8000
Apr 25, 2018 6:39 AM CST

I started my garden clean up April 23. The first nice day in upstate NY. 1/2 my Iris plants had yellow/brown leaves. I cut them all back to 6 inches above the ground. I will admit I didn't do any research on this I just clipped away. Now I am researching cutting back bearded irises and fear I made a terrible mistake. This is my first time having irises in my garden 😔
Earth, Rain & Sun
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Apr 25, 2018 7:12 AM CST
Name: Mary
Tennessee (Zone 7a)
Bee Lover Peonies Native Plants and Wildflowers Irises Keeps Goats Dog Lover
Daylilies Composter Cat Lover Bulbs Butterflies Keeper of Poultry
I cut my leaves back in the fall in order to neaten up the garden. The iris have never seemed to suffer.
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Apr 25, 2018 7:32 AM CST
Name: Tom
Southern Wisconsin (Zone 5b)
Butterflies Vegetable Grower Keeper of Poultry Irises Keeps Horses Dog Lover
Daylilies Cat Lover Region: Wisconsin Celebrating Gardening: 2015
Mbl8000 I doubt if cutting back the leaves that early will have any negative affect on your plants. They will start to produce leaves rapidly now that spring has arrived, and proceed to grow. Most often we remove all the spent leaves in the spring. Sometimes the tips of the leaves are brown and dying, and we cut them back to where they are green more for cosmetic reasons then anything. Most irises are very forgiving. Smiling
Politicians are like diapers, they need to be changed often, and for the same reason.
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Apr 25, 2018 1:08 PM CST
Name: daphne
san diego county, ca (Zone 10a)
Vermiculture Million Pollinator Garden Challenge
Welcome! to the iris for mbl8000! hope you stick around, the blooming season has begun for many of us and is beginning for others. Green Grin!

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