fall cut back on iris?

Hi yall,

could sure use some help with following question. can i cut back the tops in the fall without damaging my next years bloom crop?

newbie

I dont think i have ever cut back any of my iris. They normally just die down to where they are ssuppose to and come back again in the spring. Then i remove any dead foliage...and that is all i ever do. I would want to see what others say though!

here is a good link - http://planttraders.ipbhost.com/index.php?showtopic=683

This message was edited Nov 19, 2007 12:49 PM

My Iris are putting out new growth right about now. Maybe you are thinking of trimming the old dead parts?
Elaine

I have heard that the only time one should cut back iris leaves is when you plant them. Then they won't have to support a whole lot of leaves until the roots grow. Then never cut them again. Those leaves are feeding themselves and the rhizome for the next crop of blooms.

Hi Georgiacat... Cutting back leaves of iris is not normally recommended, as the leaves do provide food for the rhizome, same with tubers and bulbs of other flowers. However, iris leaves that have become floppy or have brown tips can become very unsightly and detract from the beauty of your garden. I spoke to one man who said he loved iris blooms, but would not have them in his garden because the leaves were so ugly the rest of the year. Point well made in some cases. I routinely (year round) remove browning tips, and cut back leaves that have become so floppy they are unattractive. I don't completely remove the floppy leaves, I ,just cut them back enough so that they stand erect. I just prefer the "clean" appearance. It's simply a matter of personal taste. I have never experienced reduced bloom from cautiously keeping my iris leaves looking well groomed. As the spring growth spurt arrives you will be rewarded with not only beautiful blooms, but nice looking leaves as well. The leaves on the iris in the attached photo are always well groomed, and the rapidly growing healthy new leaves always provide a nice display. Good Luck with your iris, Dan

Nice looking foliage, Dan !!

Thanks grannymarsh, I appreciate your compliment... Dan

Man my beds should look so good!!!!!!!!!!! nice job Dan
Gloria

Dan, so beautiful. Mine are so disorganized especially now that I see yours. What are the complimentary ground cover flowers in front?
Deborah

Hi fellow gardeners,
I wish to thank everyone for their comments and feedback,each time i return to Dave,s Garden
site i am overwhelmed by the number of people whose main love is flowers. I guess in a way i
envy you, for my summers are spent in the Yukon ,so i see my flowers first thing in the spring,late fall and through photo,s my neighbor is kind enough to send me.The flowers i see are undomesticated and growing wild in the wilderness, none the less the beauty is breathtaking.
thanks again,When i figure out how to operate this laptop i promise to show them.

georgiacat.

Gloria... Thanks for the nice comment.

Deborah... Thank You. The flowers growing in front of the iris are violas. A great substitute for Pansies in our warmer climates. I still grow a few pansies, but I like these much better. Such bright, happy little flowers. Planted in the fall, they will grow basically unattended through the winter and until the weather begins to warm substantially. The photo was taken on March 31st. I've included another image of the clump growing towards the rear of the photo.

georgiacat... You're welcome. I hope we've been of some help. I would love to trade for a few weeks of that summer Yukon trip. Such an awesome place.

Dan

Yukon.. as in cold. I bet there are some beautiful flowers up there.. uh,, now we have to keep reminding ourselves about those 100+ temps. back in August, right? LOL,, I love those 'johnny jump ups' violas
Elaine

Hi I only clean out the dead and ugly leaves, I was told by a grower that there is stored
nutrients and water in the leaves, I would also think it is a form of protection for the rhizome itself. I am sure in the cool climates they would need that much more protection. thanks Marie

We're in a cool climate up here and I always remove the old leaves. They prove to be good hiding places for slugs, earwigs and it's so easy to cut them back and eliminate the problem.

That's what I was wondering about--the opportunity for iris borers and such to hide in the brown foliage....?

Can someone remind me when we treat for the iris borer, by the way? Is it early spring? Yes, I have the dratted things in my garden!

Hi zacattack,

thanks for the feed back on the iris, if your ever in the Yukon from May thru sept. i would be happy to share some the places i have found.

Robert

the moth responsible for iris borers lay eggs on dead iris folliage
How ever they do not hatch until a warm spell and putting triazide or merit down early spring will help take care of them. I was told do not cut back follage as it will fall off on its own and help protect the rhizome especially where there are freezing temps and little snow. By allowing the green shoots to stay as long as possible the rhizome can get what it needs from the sun. I would only removed desised potions, treat as needed and clean up well in the spring early.

Have a great winter everyone
:)
Anita

Thanks. Will do, avmoran.

I've been digging up information from several previous threads on this forum, and I'm trying to clarify a point...

If you know you have iris borers in your bed, is it then a good idea to also cut back *all* leaves in fall or spring? Or do the borers really lay eggs only in dead and dying foliage?

Thanks!

critter-- I don't quite understand the steps, either...

I guess I'll treat with the pesticide in March and hope for the best. I already dug out the iris afflicted with the worst cases and threw them away...and cut back as much as possible...I hope I didn't kill them, but maybe that's what needs to be done, anyway... oh, well.

I just got the following response from an expert via Dmail:

"When gardening within the borer's range (regardless of whether or not borers have been identified in your particular garden), any foliage which was not removed in fall should be removed all the way down to the rhizome before active growth begins in the spring, and definitely before temps reach 70 degrees."

Since there are borers in my area of MD (hopefully not in my garden, but you never know), I'll plan to trim back all foliage and then treat with imadocloprid granules next month.

I am the so-called "expert" critter quoted above. In my own garden, I rarely do any sort of fall cleanup. I allow old foliage to winter over to give the rhizomes a little extra cover. In early spring, preferably before the irises have broken dormancy and begun active growth, I do a thorough garden cleanup with scissors in hand, cutting off all iris foliage as close to the rhizomes as I can get. If I'm a little late with this chore and the irises have already begun growth, I'll go ahead and cut off the new growth along with the old just to make sure I remove every bit of last year's foliage and any borer eggs it may harbor. I throw the cleanings away - do NOT compost.

As soon as I have the beds clean, I treat them with imidacloprid granules and water them in well. Early and thorough clean up, and early treatment with imidacloprid have effectively eliminted borers from my iris beds.

Laurie

lauie, your expertise isn't so-called at all -- I just didn't want to attribute a Dmail quote without permission. (Some people get touchy about things you wouldn't think they'd consider "private," so I consider all Dmail private until I ask specifically when/where I can post it).

Thanks for your help!

How do you know if you have iris borers? The deer keep my iris leaves short over the winter. In the spring there are other things for them to eat and they leave them alone to grow again. I guess I have my own free iris pruners.

I just googled imidacloprid and found this article on wikipedia.

http://en.wikipedia.org/wiki/Imidacloprid_effects_on_bee_population

It's illegal to use it in New York.

No problem, critter. I just always cringe a bit when I am referred to as an iris "expert".

I have never actually seen a borer in my iris beds, but I know I had a lot of them years ago before I started applying imidacloprid every spring. When borers were present here, I dug up innumerable rhizomes that had been hollowed out and left to rot by the little beasts. I also frequently saw the telltale "wet" streaks on the leaves. I can't explain why I never actually found a borer. I suppose perhaps they were already pupating by the time I dug my beds and found the ravaged rhizomes.

Laurie

pirl, do you have a website URL that cites NY's ban on imidacloprid? This is the first I've heard of it.

Thanks for the info. I'll put the iris clean up on the calendar for early spring.

I suppose the iris borer likes siberian iris, too?

Laurie, you're an expert in my book! How would you like to be referenced? As an "iris grower" or an "irisarian" or...? Somebody, help me out!

When you quote somebody, you're supposed to establish their bonafides...

Nobody listens if you say, Joe Schmoe tells us we should always sand before we prime and prime before we paint... But if you say Noted Victorian restorationist Joe Schmoe tells us.... then everybody perks up their ears. ;-)

I suppose I am an avid iris gardener with 12+ yrs of experience growing both bearded and beardless irises in the challenging climate of northern Minnesota.

And yes, borers will go after beardless irises, as well.

Thanks, Laurie! I'll put that in the footnote... :-)

Laurie has been very kindly giving me input on an upcoming article on spring tasks for bearded irises, including borer control... it's an article for newbies like me (I've only been growing irises for a few years, and I know how much I don't know!), so I really appreciated her advice. Thank you, Laurie!

Laurie--do you know if the borer likes Siberians, too?

Yes, tabasco, I mentioned that in my last post. Borers will go after beardless irises, as well. I think they prefer the big, fat tall bearded rhizomes, but they will dine on whatever type of irises they find available, bearded or beardless. I treat all of my irises - beardeds, Sibs, and other beardless - with imidacloprid every spring.

This message was edited Feb 11, 2008 10:26 AM

So does that mean I should also cut back all the foliage on my siberian iris in the spring? I've got a few big clumps in one corner of the garden, and I'm never quite sure what attention they need from me...

Yes, definitely cut off all of that old Sib foliage before they break dormancy. Dead Sib foliage is terribly messy, anyway. GET RID OF IT!

Yes, ma'am. :-)

Last year, I sort of pulled most of it away from the clump and threw it out. Cutting sounds easier.

Here's part of Bayer's response to an email I sent them when I couldn't locate their product locally:

The active ingredient in Bayer Advanced Tree and Shrub Insect Control is Imidacloprid. This should be an effective product for that pest. However, all Imidacloprid products are restricted in the Long Island area.
*******************

So I called and asked what "restricted" meant and they told me it's banned in New York.

critter, cutting old Sib foliage is safer for the plants. Sometimes stubborn old foliage can dislodge rhizomes if you really have to tug at it to get it out of the clump.

pirl, thank you for that extra clarification from Bayer. Did they explain why?

thanks. I'm sorry I missed your first reference to siberians.

Gotcha. I'll take a whack at it with my machete... no way will scissors do the job, LOL.

Thanks!