NCRescue - that is so exciting!!! 12 years is a long time, but it's not forever and we're three years in now. Congrats on your hard work paying off, and thank you for holding up hope for the rest of us.

Wisconsinitom - the significance of the seeds is related to the article you didn't have a chance to look at and what it says about ants as a vector. I'm very familiar with those darned rhizomes! But sometimes they spread in ways that seem impossible without the help of something and ants was one possibility posed, but the article only references them eating the berries. Hope that clarifies a bit!

Radiant, roughly speaking, where are you? This makes a difference in how this plant behaves. Here in Wisconsin, for example, it can be grown safely. That is, its spread is controllable.

I have actually seen much worse spreaders (aka japanese anything (wisteria,honeysuckle, kudzu for example))....here in Arkansas.

Vines are particularly bad, but invasive properties vary according to geographical sites, and even within those broad areas, there can be differences of wet/dry, acidic/neutral, etc., that will affect just how invasive plants can be. I think this particular species, since it really shows up in the late winter here, gets overlooked in many gardens until it is rampant, thus a big problem.

In March I bought some heavy landscape fabric from a greenhouse supply plus some U-shaped metal stakes. Overlapped 2 long stretches of fabric and staked them down well over the infestation area. Covered it in heavy drainage rock (it helps to have teenagers with money incentive for this). It is now September and haven't seen any yet. If any peek out I have some Speedzone on hand which worked in a couple small clumps in another area. Had to buy it online as I couldn't find it locally.

Good job! And the kitty watcher is great, too.

thanks! That area was a mess back there, covered in ivy, blackberries and arum. Had some nephews over for a couple weekends and got it all cleared. The ivy has stayed away mostly, but I think I'll need to spray the blackberry shoots this fall. Digging them up is not working. I have had no arum problems since I covered them, but I will update later on in the spring. I forgot to mention I put Casoron down first before the landscape fabric. Figured it wouldn't hurt, but it's probably not necessary if you're trying to avoid chemicals.

Personally, that "landscape fabric" is a mistake. I see the organic mulch material about to be spread over the top of it. That stuff decomposes, dust and soil blows in, weed seeds blow in, and before you know it, you've got weeds anyway, plus an icky unnatural layer between the crucial very top layer where all the organic matter is and all the life, and the deeper soil layers. Air and water movement is disrupted by that stuff. Not recommended by modern landscape protocols, plus, the presence of that impervious layer means none of the good stuff from the decomposition of that mulch is a wasted opportunity.

Hi All, I just wanted to report that after years of trying various products and also just digging them up (which never really works as there is just about always a few bulbs left behind, even with sieving) I have had some luck on quite a large test patch in my 1/2 acre garden. I used a simple Round-up wipe-on Gel, available from any hardware store. First I applied it as directed to the top-side of the leaves - after waiting three weeks this seemed to have no impact whatsoever. Next I tried wiping it on the underside of the leaves, they seemed a little yellow and sickly after two weeks, so I repeated the application on a two-metre square section of my initial four-metre square test patch. Interestingly, the areas that weren't treated twice seemed to recover, but ALL the arums in the patch that got wiped twice died! It's been over two months and they haven't returned in that patch, also, as it is a wipe-on gel, the other wanted plants are unaffected. I'm now rolling out a campaign to treat the rest of the section. So, in summary, wipe the underside of the leaves, repeat the treatment after two weeks. Let me know how you get on.

Congratulations! I never heard of a wipe on gel but will check on it to help get rid of monkey grass/loriope that has invaded everywhere. I dig lots of it, but sometimes there is just too much. Thanks for sharing your "report."

This is the stuff I used: https://www.youtube.com/watch?v=P2QKI6bX0nw. However, note it didn't work on the top-side of the leaves (which are quite waxy), and it required a couple of applications - it is easy for a home gardener to use though (as opposed to sprays which require mixing and are hard to target).

Wow! I will certainly look for it!! Thanks again.

I have successfully eradicated arundo donax, yellow nutsedge, cogon grass, phyllostachys aurea, etc from their toughest footholds on where I do not want them, each over a three year span, about the same amount of time the herbicides take.

But, rather than killing off good organisms, I introduce more by doing one thing: burying the weeds at least a foot deep under slow to degrade trimming chips from utility trucks, and sometimes even deeper with 3 by 3 by 3 foot brush piles. I do this a small section at a time manually to give the microbiomes time to adjust.

After the first year the top layer of the bad roots slide out with a potato fork. The second year the mulch loosens the soil deeper, so the middle layer of bad roots slide out with my potato fork. You can extemporize my third year results.

Maybe this method works for the alum. Pine straw has worked as has gallons of used coffee grounds on various tough rhizome plants for me where I cannot drag chips. Bales of straw plopped unopened on top of the newly cut weed patches can work. Then the straw is already there for future good gardens.

I respect the idea of altering ph in some situations. My goal with mulch is to cause weeds to grow SPINDLY with roots too deep to hang on with, easy to pull. What I do not pull by hand I cultivate with a three pronged rake and mulch some more. My surrounding desired native plants flourish from the improved soil.

I do this in kudzu and air potato land. Once I began to see the benefits of mulch, the possibilities became seemingly endless.

Here in Dallas, this plant spreads far and wide. Seedlings come up over 100 feet from the closest seed source, so more than just ants must spread it. If I had it to do over again, I would never have planted it. But I did, and it really is pretty. Mine are "Marmoratum." They have variegated foliage in winter and spring, 8-12" white spathes in late spring about the time the leaves begin to die, and Arisaema-like masses of red-orange seeds in summer. I don't like that it comes up all over, and I try to pull the seed clusters while they're still green, although I inevitably miss some. All in all, though, in this climate it doesn't seem to actually crowd out anything else, and it grows happily in deep, dark shade through the dead of winter. I try to uproot any new seedlings, but the variegation doesn't appear until they get to about 4-6" high, so they're easy to miss, and by the time they become conspicuous, pulling or digging them only seems to induce them to multiply. I have other weed problems that are far worse: Asian jasmine, white ash, privets, hackberry, yaupon, pecans, oaks, Bermuda grass, Zoysia grass, blackberries, poison ivy, snailseed, wild grapes, Callery pears, Mexican plums, wild germander to name only some. Again, I wouldn't have planted it if I had known how it spreads, but the genie's already out of the bottle, and I have worse weeds to contend with. Of course I don't live in Portland; it sounds as if it's a plague there.

Hi, I live in Britain, and am trying to find a way to get rid of this myself too.

It seems strange, that although this plant is so invasive, that people continue to suggest sharing it? I'm unclear how it spreads, but last year I only had one or two specimens and this year I have hundreds. I am so sad, as its taken a lot of hard work to get my garden to the point it is now. I feel like its all going to be undone by this poisonous species. I hope you find an answer.

At some point I realized that Jim6810 and I not only live in the same town (Portland), we are old friends! He is the one who first pointed it out to me in the yard of our then-new house. Anyway, his latest theory (and I find it convincing) is that worms are one way it is spreading. This makes sense to me because of the patterns of the paths it makes in the lawn (keep in mind that we haven't let it go to flower and seed for four years now). I didn't have much luck with Speedzone. Digging has had an impact in some areas, including almost completely eradicating in some smaller areas. Our next step is going to be to divide the worst area into four parts and try different approaches in each: heavy mulching and manual removal of what comes up; mulch + spraying what comes up with glyphosate; no mulch and spraying what comes up with glyphosate; cut & paint the ends with glyphosate. The most worrisome trend is the bits spreading through the lawn. This year they are tiny leaves and we're plucking them as they come up. Anyway - that's our spring update!

Edited to add link to article on earthworms as weed spreaders: http://wssa.net/2008/08/underground-gardening-by-earthworms/

Here in TN the spread over 57 acres is frightening! After much reading, I have begun what will be a 3-4 year project to eradicate Arum. It is most obvious in winter. I am spraying SpeedZone with a sticker spreader and making sure the undersides get sprayed. Since this is a huge area, it takes weekly walks with a 1 gal sprayer to spray and re-spray patches that have developed over about a ten year period. We have lived here for 30 years. Gardening is my life. I just started this process a month ago and I see progress, but I also see new leaves sprouting from the clumps. It grows from bulbs. Do not dig, the bulbs break off and regrow. It is December now. I expect to patrol and respray through the next two months. After that, my regularly gardening cycle will demand my efforts. If I continue this program starting next November, I expect a real improvement. This plant, though pretty, is a true minis.

You will have to do it multiple times. This thread started many years ago,and the original garden still has some...but it is finally under control.

Yes, This is Not the first time I have sprayed the evil stuff. I cannot believe it is still being sold, and on Amazon no less. I wrote in and told them what I think of it! I am a master gardener and hope to get the word out further. It shows up so much better this time a year.

I am now volunteering at a different garden from the original poster, and guess what, Italian arum is one of the worst offenders. I feel as if I am starting all over again! There is also lesser Celandine Ficaria verna, which was mistakenly planted as marsh marigold. I cannot tell you which is worse, but getting these two under control will be another decade plus project.

Wow, unbelievable discussion about Arum. This stuff is a bummer but is it possible to lighten up a bit? It’s not evil and it doesn’t belong in your microwave! I’ve got it and it’s annoying, but to me it’s actually satisfying to just dig up. Get your spade and get a workout. Have a water bottle nearby, smoke a little somethin’ and make it disappear for the season. Gotta dig deep but the roots show themselves bright and easy to follow. I fill up wheelbarrows and load them with other yard debris to take to the local forest recycler. Please consider using your physical ability and muscle over Round Up! It’s cheaper, better for you and it doesn’t support a totally lame corporation. Round up is the easy way out and it doesn’t even work for just about everyone here. I won’t buy it.

I agree with you. I just dug up about a bushel basket of it today, but I don’t hate it. It really is pretty, and it grows in deep, dark shade that not much else will tolerate. The white-variegated leaves really brighten dark areas in December, January, and February. After what I dug up today, I’m going to let the ones I missed alone, let them bloom, and I’ll try removing the red berries later in the year to keep them from propagating further.

I planted mine 20 years ago and they are thriving and providing seed for volunteers at at least 12 neighboring houses—I feel bad for that, but the genie’s out of the bottle now. All in all, it’s very moderately invasive here in Dallas, but it’s not the same sort of menace that Japanese honeysuckle and privets are.

I too live in Portland and just learned about this plant and yes I have a lot of it. I decided to dig deep and sift the soil over two grades of screening. I found lots and lots of corms. Here is my question: If I have sifted out most of the larger corms, will the little ones still sprout or will they just die a natural death because they are no longer being fed by the leafy plant? Any thoughts?

Yes, the little corms will sprout just fine all on their own :-)) This plant IS a listed invasive in many areas of the country and especially here in the PNW. There is a 2 acre patch of it that has colonized Lopez Island in the San Juans!!

Control is difficult. Digging just serves to spread the corms around unless you are extremely thorough in sifting them out. And it is not very receptive to herbicides - the leaves have a very waxy cuticle much like English ivy that resists herbicide penetration. And herbicides seem to have little effect on killing off the corms or tubers anyway. Treated plants will often resprout rather rapidly :-)

Damn those little buggers.

I wouldn't be comfortable using any herbicide that has a nearly 2 year residual effect in the soil.

I am in the process of carefully digging a bunch of these horrible weeds up - I now call them "devil weeds". I'm digging deeper than I hope the many tubers for each leaf, it seems, live and taking every tuber I can sift out and throwing it in a black trash bag and then into the household garbage. Some of the tubers I've found are as small as the seeds on a blackberry so it takes a lot of time and patience. I'm hoping this is going to work!

Thanks to everyone who has posted on this thread over the last 14 (count 'em) years.

We moved into a 4000 sq m garden here in the central west of NSW earlier this year and as I have explored the garden I keep finding clumps of this horrible weed.

So far I have found that AI laughs at Roundup (at least when it is applied to the tops of leaves) and that digging it up and sifting out the tubers and rootlets is quite therapeutic. I am going to try the suggestions here until I find one that works for me and will report back.

I have a theory, that maybe it's not really Roundup resistant, just that Roundup is most effective when plants are in active growth and Roundup is ineffective when temperatures are cooler.

Since the arum grow in late fall through winter, and add in glossy run off leaves, you have a situation where Roundup doesn't work well. Just an idle thought, in effect yeah Roundup doesn't do the job here ;)

I was at a Christmas in July lunch today and one of the guests was keen gardener (age 92). She recommended cutting the leaves off the stems and painting the top of the stumps with mineral turpentine(mineral spirits in North America)which she suggested would kill the bulbs. Any thoughts? Turps is a possibly a bit toxic to other living things, such as frogs which is one reason I am not keen on Roundup etc.

Has anyone managed complete eradication of a few relatively contained large patches? I have around five clumps in my yard, and after reading this whole thread, I'm irrationally terrified that it's going to take over my entire property/make my future gardening a nightmare...I'm in zone 9b, and have let it hang out in my garden undisturbed for around 3 years. It doesn't seem to have spread far and wide like some others have reported, but it's definitely spreading in the shade of the trees it's under, and I'm extremely nervous that it'll contaminate and colonize my other acre, which is damp and shady. I've dug up a couple patches, and definitely missed some of the corms -- they really do explode when you dig them up! Does anyone have any positivity/advice for me at this stage? ncrescue, did you manage to eliminate the early infestation on your own property? I must admit, I'm panicking a little over here, lol! I can't seem to find any reports in which someone successfully 100% eliminated this plant, and I've looked very hard...it's extremely disheartening! I'm worried that it's going to spread and affect my neighbors, or that if I someday move out, the next person won't be able to keep on top of it. It's just soul-crushing, especially since it only recently appeared in this area. Worse, I have chickens, and they love to scratch at the disturbed soil and presumably throw the corms everywhere...eek!!!

I have sort of given up. It is everywhere. I try to cut it down to the ground at least, and I cut off the red seed pods or whatever they are and throw in garbage to keep birds and squirrels from spreading, but other than that, I almost think leaving it alone is the best thing, as any digging or spraying seems to make it stronger. Once in awhile I'll burn a patch with the weed burner, but nothing makes it go away permanently. Take a deep breath and admit defeat, I think:) Sorry I can't be encouraging!

Ah, good to know...thank you for your candor, joni2717! I'll adjust my expectations and aim for minimization rather than eradication. I guess that since it appeared it my garden in the first place, it would probably reappear even if I DID eradicate it! It's currently confined to a 5' by 5' region, so I do have some hope that I can reduce/contain it still, especially since I'm on the edge of its preferred climate, zonewise...we'll see! I'm going to dig up all the plants I see and pick out the corms as much as possible, just to see if it weakens the clumps at all, especially since others have reported some success. I'm not sure why I was so disturbed by its presence...I guess it's the fact that it's new, and I don't know the extent to which it might spread, unlike other existing invasive plants on my property. However, it's not like invasive plants on my property are new...I guess that to some extent, invasive plants and weeds are an inevitability in the garden, and I'll just have to add pulling Arum leaves to my list of spring chores. At least this one happens to be pretty! :) I've certainly let it set seed for the last time, lol. I'll check back in months/years to report on my results, and I encourage others to do the same...it's nice to know what you're up against, even if it can be stressful to hear at first! And to everyone else who's struggling with this plant: I know that it can be horribly frustrating not to have complete control over the species in your yard (I could really do without the star yellow thistle, personally!), but I'm sure that your gardens are beautiful anyway. You're all doing great! :)

Wow... this is depressing! We just bought a home on about 2/3 acre, and I would say that 1/3 to 1/2 the yard is infested with this stuff. Yikes. Here's my question: I'm seeing reference to growing cycles, catching it as it's emerging, etc. I live in northern Alabama and have no idea what the timing of this plant's cycle would be in our area. Can anyone help? I believe we are zone 7a. Thanks in advance for any advice!

I worked on the property described by the original poster, and I can say that after years of spraying and digging, it is "almost" gone. Now, I have to worry with a small patch that apparently came to my house from plants I received from this garden. Sad.

I've had pretty good success with using Round Up Gel, wiped on the UNDERSIDE of the leaves as they appear, and digging any larger clumps. I would say I've now got the problem down to a very minor level (small isolated clumps that pop up in hidden places) compared to how it used to be (spread over almost 1000m2!). I think it is something you have to keep on at, otherwise it could re-infest - like aluminium plant in my garden.

louise453 - what dilution do you use with Round Up?

Hi Albert, I use the ready to go wipe on gel, there are a couple of different kinds here in New Zealand - they both seem to work fine: https://roundup-garden.co.nz/products/roundup-gel

I have had good luck pulling up the plants. The key is to pull them up immediately, as soon as you see the new shoots breaking the ground, and to be persistent (this works with oxalis, also). Don't give them a chance to re-charge their roots. After a few years the corms are exhausted and no more arum. Now I'll get an occasional shoot, maybe one or two a year, which I pull asap. This works quite well with small infestations and demonstrates why an arum invasion should never be ignored: they can be successfully exterminated, without toxins, when they're SMALL.

I thought I'd update the situation here on the Central West NSW frontline.

Quite by chance, I adopted from last winter the strategy suggested by Katherine D immediately above.

As I enter the second winter of the campaign I am finding a lot less plants coming up and because the soil in the flower beds has been turned over lifting the plants complete with corms is straightforward.

One thing I have found is that the plant is extremely resilient. As I dug up arums last winter I put them into used plastic animal feed bags which I left out in the sun. Over the summer we had +40 deg C days and low humidity and in my innocence, I thought that would do the plants and corms in. Come the late autumn I started burning the contents of the bags in the fire pit and lo and behold there were corms sprouting happily away. And even after exposure to the flame, they had to be in the very hot part of the pit to ensure their destruction.

One final note: our local Agricultural show here in Canowindra is held in spring. In fact it is more than just sheep and the big money local crop, lucerne, there's a horticultural section too. Taking in the prize-winning exhibits last year my eye fell upon one "highly commended" potted specimen, a ''beautiful'' arum.

I wrote to the PA&H Show Society to complain that they were encouraging the cultivation of a noxious weed and a threat to pastures. They acknowledged my letter. It remains to be seen if they can the class for arums this year.

I just saw these in the discount bin at Walmart. They are only very mildly invasive here in the Dallas area, Zone 8, but I wondered how, in good conscience, they were still offered with no disclaimers. I suppose the same way Pistacia chinensis is still offered here, or Nandina domestica, or various Pyrus calleryana cultivars. Those are real menaces in this part of the country. A few plants have been banned here—Sapium sebiferum, a/k/a Triadica sebifera; Eichhornia species; non-native Salvinia species. When I lived in NYC, Japanese knotweed was banned. I suppose every region is susceptible to different weeds. Anyway,, good of luck to those of you in the PNW. In controlling this one.

We’ve just found out it’s on a property in Tasmania we bought. 5 acres, with one large patch about 30 metres squared. The previous owners obviously used something nuclear on it as it’s springing up out of dead patches where nothing is alive.

Our conservation advisor recommended metsulfuron for the large patch, which I’m afraid we’ll probably have to use. But I can see it popping up in other places throughout the property in new small patches, and have found that there’s only a few of the tubers there so digging out new patches before they get established seems paramount, and avoids overuse of pesticides.

Will update here with how we go, I realise it’ll be a multi year battle but I’m starting to see how we’ll get on top of it.

I have just read this whole thread and am glad to have finally found some information about this terrible lily. We bought our place in southern Tasmania 5 years ago and I have been trying to get rid of these lilies since we arrived by digging them up each year. They just keep coming back and I seem to have just succeeded in spreading them further and am tearing my hair out! I might have to resort to the round- up gel ( I hate using chemicals but am getting desperate... )I have thought about trying to smother them with plastic for a year or 2 to see if that works... has anyone tried this? I’d like to put in some raised beds and wondering if they will just come up through layers of newspaper... I’ll try and let you know. Thanks everyone!

I read this thread annually. Round up does not work, nor does my vinegar sugar salt mixture, though interesting what someone said about spraying underside of leaves.

I paid a crew to meticulously dig down and get all the corms, (witnessed the corms coming up, and have done this for two years in a row, and the problem is worse every year. (I'm in Portland). I'm convinced you do not want to disturb the corms or they will simply spread. And I no longer transplant anything in my yard as I've noticed that a tiny corm always sneaks in to the transplants.

My new strategy: using a weed torch, For round one, I blasted at the base of dirt and stems. In another week, I'm going to clear the soil and dig down just enuf to expose more of the stem, and blast the weed torch in the direction of the corms. I'll keep doing rounds of this and see what happens. Funny thing is, the evil arum all disappears in the summer and you think it's taken care of, then comes back with ferocity in late winter.

I have tried the weed torch too. If you can actually get the corms, that is good. And yes, digging it out only spreads it. For the first few years we lived here I tried digging it out, and only succeeded in spreading it all over. So now I ignore it, torch it, or just cut it to the ground whenever I see it, depending on how ambitious I'm feeling. And I know I have said this before, but for any new people looking at this thread, PLEASE do not use pesticides/herbicides of any kind. They will kill your other plants, and eventually make everyone around you sick and poison your soil, but they will NOT kill arum italicum. After we bring about the destruction of the planet with all our poisons and petrochemicals etc, cockroaches and arum italicum will still exist!

Since my post above I have diligently pulled the arums as soon as they poke their little blades out of the soil. Every year there have been fewer arums coming up and they look pretty scrawny, but I expect that I will need to be forever vigilant. Not only are the corms resilient and impossible to completely get rid of but, thanks to neighbors, arums elsewhere are reaching maturity and going to seed. Birds feed on the seeds and leave little gifts wherever they perch.

Cholla51

I live in Coos County OR. and have it too! It's kinda like herpes, (no I don't have that), the gift that "keeps on giving". Well, not unlike herpes, it is a rhizome that spreads via seed-lets that fall off the main parent seed especially when turning the soil./ They are very small 1.5mm+/-.

I shovel under the clump and bounce it a bit to reveal and loosen the soil the main plant stem is in. They are easy to see and remove when you are on your knees, sifting through the clusters. What looks like just a dirt ball about the size of a pea +/-, is actually a seed that hasn't sprouted yet.

It may take several diggings in a year however, but better than supporting the petroleum beast which, by the way, I was considering. Do it when the soil is damp and easier to dig. On a side note, the seed itself seems to be high in starch. Maybe a little sea salt and roast them? ;-/

I do not like herbicides, so I have been digging and tossing whole clumps into trash bags, soil and all. I find it hard to distinguish small tubers from soil clumps and small rocks, and this method prevents them from going back into my bed. It is wasteful of soil, but I had awful, rocky soil, which I am slowly replacing with homemade compost. After three years of doing this, I only find an occasional plant.

Susan

This is my favorite thread of all time and I realized after posting on reddit about arum that I should return here since I've referred people to this thread so many times. We are on year 12 and have made slow progress. Switched to primarily hoeing and weedeating the leaves to start it out. Our bigger clumps we mostly dug out. We also had some success in a larger area by smothering with chips and then weed eating what came up. Long, slow process.

Anyway - the Institute for Applied Ecology recently (2025) presented their findings from a three year study that will be interesting to people, although they don't have any silver bullets. Presentation: https://youtu.be/BCMayHrU1Mg?si=qKkxG7_hMX5eVsZQ

Paper: https://appliedeco.org/report/assessing-management-treatments-for-controlling-invasive-italianarum-arum-italicum-2025-final-report/