Iris pest

Mom has tons of generic unnamed iris that she brought when we moved her here from Tulsa. They have developed something that is, I think, eating the leaves. The leaves kind of look shreaded vertically? Even with the bifocals, I can't see anything for sure, maybe something white but not sure, it's that tiny. Someone recommended digging them all up, and washing the bulbs in bleach solution.

THATS not gonna happen! Mom can't dig them, and I do not have that kind of time or energy. Can someone suggest something before I get guilt tripped into digging literally hundreds of iris bulbs out of hard rocky soil full of goatheads?

Please?

Picture please.
Inanda or even pictures plural.

Ok, took pics, but have to wait til DH gets home to download. Heaven might know where he put the cable, but I don't.

Pictures.

2nd pic.

3rd

last...

They seem to be only in the iris, although they are in several different beds of iris. And the camera shows the white better than I can see it.

What do I do?

iris borers come to mind. hers something i got about them from a web site




Iris borers spend the winter as eggs on old iris leaves and plant debris at the base of iris stalks. In early spring, they hatch into tiny caterpillars and climb up new foliage. They chew pinprick-sized holes and tunnel inside leaves as they continue down toward the rhizome. Their feeding causes streaks that appear tan or water-soaked. Later, the tips of infested iris turn brown and appear to senesce (age prematurely), although the entire plant seldom dies.

The caterpillar tunnels through the leaves reaching the rhizome by mid summer (July in Minnesota). At that point, caterpillars have grown to about 1½ to 2 inches in length. Iris borers do severe damage to iris by consuming the rhizome. Iris borer feeding can allow the entry of a bacterial soft rot. Rhizomes infected by soft rot are slimy, soft and foul-smelling.

There are several iris diseases with similar symptoms that can occur when iris borer is absent, including bacterial soft rot, iris scorch (probably caused by a phytoplasma), and fungal leaf spot (Didymellina macrospora). All of these disease organisms will cause iris leaf tips to brown and iris plants to senesce, mimicking symptoms caused by iris borer.

In late July or early August, iris borer caterpillars move into the soil where they pupate. They emerge as moths in late summer or fall. Female moths complete the life cycle by laying eggs on old iris plants in August and September where eggs remain until next spring.

Management

Management of iris borers is difficult. However, there are several steps that can be taken to reduce their damage in gardens.

Resistant varieties
Although all types of iris may be infested by iris borer, Siberian iris are more tolerant to iris borer attack.

Sanitation
Proper sanitation is important. Check iris during spring for evidence of chewing damage and water-soaked streaks. This injury can be easily overlooked so look carefully. If you discover iris borer damage early in the season, you can crush the insect while it is inside the leaf or remove the infested leaf.

Sanitation in July is critical if you are having problems with iris borer. If an iris plant has above-ground symptoms (brown leaf tips, early senescence), dig it up and examine the rhizomes. Discard rhizomes containing iris borer caterpillars and those with tunnels.

During fall, remove and destroy (e.g. burning or burying) old iris leaves, stems, and any nearby plant debris. This removes and kills overwintering eggs, minimizing the risk of iris borers next year. Clean up iris beds anytime after we get a hard frost when female moths are no longer laying eggs.

Insecticide
A well-timed insecticide application can help reduce an iris borer infestation. Two options are acephate (Orthene) or spinosad (Bulls-Eye). It is important to time the application when eggs are just hatching. This is approximately when new growth is about four to six inches high. A repeat treatment 10-14 days after the first application may be necessary. Dimethoate (often sold as Cygon 2E) was a commonly used product for iris borer management, however it was canceled in 2002 and is no longer available.

If your irises have been unaffected in the past, you do not need to use an insecticide to protect them. Maintain good sanitation practices to prevent problems and to help detect an iris borer problem when it first begins.

Natural
Beneficial nematodes are a natural option to help control some boring insects. These nematodes are microscopic worms that seek out and kill the caterpillars by introducing a bacteria. Research results using nematodes have been inconsistent, although they can potentially be effective in reducing iris borer populations.

Two species of nematodes are commercially available from natural garden supply catalogs or your local garden center. Both species (Heterorhabditis and Steinernema) have been shown to attack iris borer. Nematodes need a moist environment to survive and move. The easiest time to apply is during a rain shower. Lacking rain, water iris before and after applying nematodes. Apply nematodes when iris leaves are almost fully expanded but before flowering. Repeat the treatment approximately one week later. Nematodes are perishable; check the label for the expiration date


http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/e122irisborer.html








hope this helps.

or, you have to dig up the rhizomes and search out the borers in the leaves or rhizomes or both and dispatch them manually. nasty work but not too much extra if you are moving the iris anyway. by the time they make it down to the rhizome they are pretty hefty and easy to spot. kill the bug cut off the affected part and trash it and then replant the rhizome.

That is the part I was hoping to avoid. These iris are in very hard packed, rocky soil, and they are undergrown with stickers. Mom brought them with her from Tulsa, and Dad planted them for her when they got here. With the backhoe. I don't know if I can get a shovel in the ground where some of them are.

I'm so sorry about your bugs! To get the Iris out of the ground you can try one, or a combination of these: If you've got hard ground, soak the ground before you try to raise the Iris and lift them. Then when it's crumbly again, add amendments, divide your Iris and put them back. That is unless your "stickers" have the ground totally compacted. You could try a preemergent with them next spring so that you don't get new "stickers". Or put newspaper in between them and wet it down, not on the Rhizomes but about 5" away. That should kill the stickers in about a month. Sunset uses it for killing lawns when they are carving out new beds. There are liquid soil softeners too but I don't know anything about them - you'd have to find out if they were toxic and not too high in nitrogen. Don't use black plastic. Ugly, doesn't work very well, expensive and can hold the heat in the ground and grow bacteria. Aren't you glad that I saved you so much money?

You probably need to divide these Iris anyway. You'll be amazed at how well they flower after you get the borers off and divide them. We'll look for photos.

But I don't even like Iris!!

Ok, now that you've all thrown rotten eggs and tomatoes! Almost every one of her iris, are the same. Plain, purple, the kind you saw around every old house in every small town we ever lived in. If they were something different, bloomed more than once a year, or something!

And I am fighting a continual battle against goatheads. They spread, both by runners, and by sticking to everything and being carried, and are almost impossible to kill. I have found another thread here on DG about ways to get rid of them, which I am checking into. They seem to thrive and get worse when it is in drought, like the last few years. But digging the iris with them there is a nightmare, they penetrate even the thickest of gloves.

We are going to try a campaign of spraying to kill the eggs, getting the nematodes, and eliminating the leaves that appear infected. We first noticed these last year, so we have a major battle I think. I'm hoping that the spraying might keep them from spreading.

Keep your fingers crossed for me.

OK, I have to ask....What is a goathead? Can you show me a photo of one please?

Thanks,
Mendy

Hey, you've got a great solution. Don't worry about them. If they've got Iris Borer, it won't hurt anything else. And it certainly won't hurt the stickers. Too bad, huh?

You make me laugh. My tree man said the same thing about his grandmother's purple Iris. Couldn't figure out why I would grow them until he came in the spring. Now he's singing another song. But I don't know if I'd grow them if I had borers. I gave up Hollyhocks because of rust, sometimes it's just not worth it. I use chemicals but I try to avoid them if at all possible and that means sometimes not growing things that I would like to - much less things that I don't like. There are lots of other beautiful plants in the world.

You don't have a problem with the iris - the borers are taking care of that. But I'm sorry about your stickers. What a pain.

Here is a link to a thread about goatheads, and some of the links there have pictures. Nasty things. Like stepping on a rock with stickers. They stick in your shoes, can get carried everywhere, including inside the house.

But I can't just let the iris die. They aren't my favorite, but Mom loves them and no one can lay a guilt trip like her. Could you watch a 70 something lady out trying to dig iris without having to go do it? I can't.

Wonder if that would work on my kids? Surely they don't want to watch their 50 something mother out there digging iris? Hmmmm

edited cause I spaced the link:
http://davesgarden.com/forums/t/491205/
.

This message was edited Apr 23, 2005 10:46 AM

Where's the link? ;-)

you're quick.

What a very nasty problem. How do the dogs fare in that stuff? I can't imagine. Guess you're back to soaking the ground. You have to wash the Iris off anyway, so you might as well. Just don't leave the rhizomes in the sloshy ground for too long. They might rot and then Mom would be sad. :-( No more purple Iris :-) I have a great idea. Why don't you get your mom to pick out some new Iris from one of the great websites? Blue J Ranch is very reasonable but they are new. They have terriffic photos. Maybe she'd be willing to part with some of the old purple ones.

If you can get your kids to do it for you = Hey! more power to you.

You're right, the dogs don't fare well. Most of them I confine to the front yard where I don't have these nasty things, and the one dog who is allowed whereever she wants, we actually went and bought booties for. It disgusts her, but it stops her getting these things in her feet and getting infected.

Mom is mom, she won't spend a dime without pinching it so tightly it looks like a quarter. I tried buying her some a year or so ago, but then that required a whole new flowerbed because she didn't have room for them in the old. I asked her if she would trade some to get others, and she refused! That would cost postage.

That dent on the side of the cement block wall is from my head beating on it.

LOL Terre....don't hit your head too hard, please! Thanks for the link. Looks like you have a very nasty problem there.....those goatheads look terrible! If I had some extra iris I send them to ya, but most of mine are just one or two rhizomes from trades I did last year. Hope you can it them cleaned up some how.

I'm not an iris expert by any form of the word but those sure look like aphids to me. So I looked up Iris Borer on Google and never saw a photo that looked like what Terre's pictures show. This is what I came up with.

http://images.google.com/images?hl=en&lr=&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&q=iris+borer&btnG=Search

This looks more like Terre's 1st, 2nd and 3rd pics.
http://www.drought.unl.edu/gallery/2002/Nebraska/Nebraska2002droughtphotos/images/hprcc_aphid2.jpg

If its aphids then all you would have to do is give a good firm spray from the hose or if that doesn't do it because they're heavily infested then spray with insecticidal soap on all sides of the leaves.

Again, I am NOT an iris expert and I've never seen or experienced iris borers.

This message was edited Apr 23, 2005 2:37 PM

This message was edited Apr 23, 2005 2:37 PM

I'll try that too. I'm going to try everything I can to avoid digging!

Brenda, I have to agree with you on that. Aphids are the first thing I thought of when I saw the little white things. They look exactly like what I get on my roses every year.

I get them on my potted daylilies and on houseplants in the winter.

Whatever you do terre - I'd cut off the dead foliage and burn it or throw it in a plastic bag into the trash. It's very damaged, and you may have more than one thing going on. You can be watching for borers while you do it. If it's just aphids - and now reading over this, they are white and you have a hard time seeing them with your bifocals, it's true that washing them out should do it. But aphids don't usually cause this extensive kind of damage.

I don't know if lack of division can cause this kind of leaf distortion. Anybody?

Took more pics, and as soon as I figure out how to work the download thing, I will post. Those do look a lot like what I have, and I went out and sacrificed an iris fan. I cut open a leaf, and inside are crawling things, some gray and some green. With legs. No caterpillars. The one I sacrificed is the one in the picture, as it seems to be the worst. The rhizome was nearly above ground, and is firm, not soft, slimy or smelly.

Aphids?

Will post pics in a few minutes. I hope.

This message was edited Apr 23, 2005 2:31 PM

My Major crop is goat heads
Did your mom bring them from Tulsa too ?
I live on the out skirts of Tulsa and their is no part of my body that has not been pierced with goat head stickers , they are like roaches .

That's a good analagy, Tazzy, they are very like roaches. Almost impossible to get rid of. I don't think Mom had them when she was in Sand Springs. She lived close to Crystal City over by the turnpike gate.

more pics,

and the inside of a leaf:

there are some that are kind of gray, and some green. Aphids?

but the rhizome looks good...

I'd get them to the local garden specialist who knows your area. Those don't look like they are going away anytime soon and they are decimating the plants. And nurserys don't charge for advice. I've never seen this kind of damage from aphids but there are a lot of things I haven't seen and pale green can be aphid color. If they're inside the leaves though, just insecticidal soap won't work. You'll probably have to take the leaves off. The rhizomes will recover though but the sooner the better so that you have fewer damaged leaves.

At this point, I would ask the most expert local person I could if I want to save the rhizomes.

There's that brick wall again.

The bugs themselves look like aphids to me. I sprayed mine for them yesterday, but they were only on the outsides of the leaves and there was really no visible damage. I've never seen aphids get inside a plant before.

Female aphids are born pregnant, so when you spray for them you must do it to kill the current crop as well as their offspring when they hatch out.

I suggest you visit your county extension service and take several of these leaves and maybe one rhysome for their opinion. Good luck!

Kay

I definitely think those are aphids, but I'm with doss....if they inside the soap won't do it. They will definitely suck a plant dry if untreated and I'd say they've been there quite a while having a party in your Mom's iris.

This link show just how bad aphids can damage leaves, so it's definitely possible.
http://www.drought.unl.edu/gallery/2002/Nebraska/Nebraska2002droughtphotos/hprcc_aphid2_JPG.html

I've been looking for a pic I have of aphids on a crazy daisy that I started from seed. Tons of plants were around it (including other crazy daisies) and they only attacked the one plant. I was not able to save it and pulled it out rather than run the risk of the other plants being next.

Here's a very thorough article on aphids. Note iris are mentioned in the list of plants they infect.
http://www.civicgardencentre.org/mg/aphids.htm

Well, hey, I was really wrong. I don't know how you feel about chemicals, but you may need to give these a systemic if you can't get enough leaves off. Sadly, another plant that I don't grow anymore is Fuschia. They get Fuschia Mites which roll themselves into leaves. You can only kill the mites with systemics and they can destroy the plants. There are a few cultivars that are resistant - but not the big fancy kind that look like ballerinas. :-(

Please don't yell at me for suggesting a chemical treatment.

Schreiner's makes it pretty clear that you have to take diseased foliage off.

I'm not a good enough gardener to be organic. I need all the help I can get. So I need insecticidal soap and a systemic. Have to get some insecticide, but have some systemic. Probably not enough though. Headed to the store.

aphids could be on the leaves, but inside them? that's got to be borers. Lift a section at a time. have a few new ones to replace the old borer destroyed ones you throw out. insectidcide the rest. It will take a couple of years but you will always have some iris blooming and you won't kill yourself. good luck,
Martha

Martha, it sounds like you've had experience with this. It's a real problem. We don't have borers here but it sounds like a heck of a lot of work.