It's only a suggestion since I like iris and have no wish to kill them. It's been my experience that vinegar kills whatever you pour it on--I keep large amounts of it on hand for killing weeds/invasive species but as I understand it, many others are similarly eradicated by it.

Good luck... and don't forget to let us know what works for your scenario.

Remove as much foliage as possible and cut the plant as close to the ground as possible. Cover the entire thing with a piece of heavy, black plastic and pin down the edges with bricks or landscape pins - anything to keep the plastic in place. Allow the plant to bake to death for the rest of the season.

The season before I planted a couple of gardens on my Blvd. I used the same technique. I covered the area with a sheet of black plastic and allowed the entire area to cook all summer. The next spring, I removed the plastic and everything underneath was dead and gone - no sod to remove - nothing. I simply broke up the soil and planted. Better yet, the cooking process seemed to kill almost all the weed seeds in the soil. I barely had a weed all summer.

Kevin

It sounds a little mysterious. What kind of iris is it ? What kind of location? Have never heard of anybody having problems with killing just a bearded one.

Some options:
-boiling water
-drowning
-covering foliage high up with dirt
-infecting it with rot
-put a cage on it with some chickens in it (works like a charm in the early spring, my chickens even did not need a cage)
-throw some slugs on it

This post was edited by wieslaw59 on Thu, Jun 20, 13 at 6:58

yes.. it would help to know.. what kind of iris ...

and i am really curious.. why you cant just dig it out ... other than you dont want to.. lol ...

trust me.. i have used that reasoning often.. lol ... but usually ended up working harder trying to avoid work.. compared to if i had just done it ....

ken

I guess I started to wonder the same thing after I made my post. I'm having a hard time imagining any iris that difficult to dig or chop out. Bearded Iris grow right on top of the ground and would simply pop out with little effort. Something like a Siberian might be more difficult, but if you start at the edges with a shovel and hatchet, it shouldn't be that hard. Simply slice it off in sections. If you don't want to dig the entire root ball out, just keep chopping off any new growth that might appear throughout the season. It will die.

Kevin

There may be sprinkler lines or underground cables that the OP doesn't want to take a chance slicing through (been there, done that - and felt like a doofus calling the sprinkler company and paying for the repair after slicing through the line). Or perhaps the plants are in a treacherous area - my sunken patio is caving in and in some areas I won't even go near the edge to tend plants for fear of falling or the ground/wood giving way.

But - I foresee the problem being only with the Siberian or Japanese iris, they have pretty extensive/tough root systems and aren't that easily dug, so yea wouldn't be difficult to damage underground lines.

If they're some type of bearded iris, they are right on the surface (some of mine actually have worked their way to the top of the soil, they seem to like be have their tops a bit unburied), so they're very easy to dig out or divide, they come right out with little effort.

Now, if OP just doesn't WANT to do any digging then we can't help with that LOL!

I do agree with Ken, though - if it's due to not wanting to dig, I think it's easier just to dig then go through the hassle of trying to kill it in a differing manner.

If this is just a matter of not wanting to dig it, you could try posting an ad on craigslist offering to let whoever is willing to dig it up take it for free. :)

My thoughts exactly, summersunshine!

Dee

"due to location, I cannot just dig out the rhizome."

Can you soak the ground and pull them up by the foliage?

tj

-

Guess I will fill everyone in a bit:)

I am trying to get rid of invasive yellow iris in a LARGE area, ie. lake. I am an aquatic invasive species(AIS) coordinator for a county that is densely populated with lakes. I do AIS outreach, and manage AIS. Right now we have no quick and dirty way to get rid of 'the yellow'. My program does not use chemicals, county policy.

We worked part of a shoreline a couple of days ago...ughhhh. There was much more of it there than we first thought. No way the rhizomes were being pulled up, no way we were going to cut them out nice and easy. I wanted to try stressing a small sample area first, then if successful attack more of the shoreline.

I wondered if someone would mention drowning, I have my doubts with these guys, but??? The shoreline we worked on we cut below the water line to try that very approach. Plan to go back in august.

There is no way we are going to eradicate the colonies, I will be happy with just controlling the edges and containing the population.

Hoping for some ideas from all of you out there:) Thank you!

{{gwi:231155}}

This is just a small sampling of what we are dealing with

That was a good one. What about cutting it down and cover it with black plastic?

Iris pseudacorus in a lake! Very different situation from I. germanica or I. sibirica in soil. I've dealt with a lot of woody invasives and I use herbicides (mostly on cut stumps). Have no idea how you would get rid of that yellow iris in the middle of the water. I'd be very curious if your drowning method works.

I re-read a few answers up above and Wieslaw I like the infecting it with rot comment! My sentiments exactly. Will think more on this one:)

And yes I like the drowning method, and will be able to tell more about its effects on the plants in August and more importantly next June.

Cutting them under the waterlevel could work. I worked at a university for a while ( something like riverbak fortification with plants, not sure about the term), and one issue I gave lectures on was establishing reeds (Phragmites australis). And those are definetely stressed by having their snorkel cut off. When the rhizom is flooded, that part and the neighbouring internodes start rotting. And the i. Pseudacorus propably should tick similar.
So we have to wait till next year...
Good luck, bye, Lin

Good grief! That is an entirely different situation than I think most of us imagined - a clump of iris growing in the garden. It kind of shows the importance of giving ALL the details in the original post.

Kind of like saying: I need to get rid of some tree seedlings in a garden. What do I do? Only to find out those tree seedlings are 40 years old and growing in a national forest.

Kevin

I love the suggestion from summersunshine in the new context.

Oh brother, you do have a problem!

Because I had no solution, I checked this Iris out on the federal database. In the section "Management Considerations", there was a long list of its various "uses"

"OTHER USES:
Pale-yellow iris has been used as a rehabilitation plant to reduce bacterial loads (review by [73]), absorb heavy metals from contaminated water ([3], reviews by [73,78]), and provide erosion control (review by [78]). One review states that it is "one of the few plants flourishing after a nuclear holocaust" (review by [73]). Pale-yellow iris was smoked by people during World War II (review by [73]). In Turkey, pale-yellow iris rhizomes are used as a diuretic, to prevent gas, and to treat eczema. Seeds are used as a coffee substitute after drying [17]. One author experienced severe attacks of dermatitis from contact with the syrupy covering of the endosperm of pale-yellow iris seeds [13]."

Hope you find a solution.

Here is a link that might be useful: Iris pseudacorus

ya kinda left out 99% of the facts in the original request for info..

lol ..

ken

Regardless, I'd remove flowers for this year. No need to add to the seedbank.

Oh, THAT thing. It is a water iris. I planted one, that I got as a bonus plant when I ordered some water plants, in a pot a some years ago and put it in my pond (I was so naive in those days). In a couple of years it had split the pot, taken over half the pond and when I went to take it out, I had to get a enlist a couple of guys to help as the thing weighed about 50lbs! Twenty five years later I still find one popping up in the garden now and then, the seeds must be viable forever.

No idea how to kill it. Is there any way to go along the water side with some kind of saw or machete and whack it off? I lnow it would be a lot of work but cutting it back and not allowing the seeds to ripen would keep it from spreading more, but you probably already know that.

Good luck with that, you have my sympathy!

Sandy

Oh, THAT thing. It is a water iris. I planted one, that I got as a bonus plant when I ordered some water plants, in a pot a some years ago and put it in my pond (I was so naive in those days). In a couple of years it had split the pot, taken over half the pond and when I went to take it out, I had to get a enlist a couple of guys to help as the thing weighed about 50lbs! Twenty five years later I still find one popping up in the garden now and then, the seeds must be viable forever.

No idea how to kill it. Is there any way to go along the water side with some kind of saw or machete and whack it off? I lnow it would be a lot of work but cutting it back and not allowing the seeds to ripen would keep it from spreading more, but you probably already know that.

Good luck with that, you have my sympathy!

Sandy

It was my intent to only post what I did. If you notice, the later posts tend more toward...'good luck, no clue', that was what I was avoiding when I originally posted.

Sometimes when you give 100% of the information, you kill creativity. I was looking for creativity and opted to give just enough info to have everyone think outside the box. I walked away from this post with some ideas, I thought I would:).

When it comes to gardening it's all in the details. The fact this was really a WATER GARDENING question is light years different from PERENNIAL GARDENING where we're talking about plants growing on mostly dry land not in standing water 24/7.

My original post to your question was a complete waste of time and of no use to you what-so-ever because I was missing that little detail about the iris growing in a pond not on dry land.

Once again, an example:

I post the question: "How do I grow lilies in my garden?"
Because people out here are extremely helpful, they start sharing their knowledge of lily culture: Asiatic, species, Orientals and all the rest. Because I know some people are really lily enthusiasts, they will probably go into a lot of detail and give me tons of wonderful info.because they're always anxious to welcome new lily enthusiasts to their group.

After a lot of people have taken a lot of time to type a lot of great information, I suddenly announce: "Oh, I'm talking about growing a water lily in a pond in my garden."
All that great lily information given is suddenly of no use what-so-ever.

Creativity?? Think outside the box? Seriously?
I can think outside the box just fine, I'm rather known for that, but I still need all the facts. That was a big, missing fact.
Kevin

This post was edited by aachenelf on Sat, Jun 22, 13 at 16:14

How about parking a large excavator on that bridge and scooping away? I see why herbicides aren't on the menu. If it was water in the west, it would be managed and maybe you could draw it down to more expose the plant. I don't really know if it has to grow in water, but maybe not being in water would make it weaker to whatever treatments you decide to try. There is iris borer. I wonder if they would eat it, or just fly away and destroy the beardeds around the area. Sorry I'm not such a good out of the box thinker, but I do wish you luck.