I hate to tell you but you now have a problem you may not be able to solve. I have seen so many attempts to snuff out this beast and all have been unsuccessful without the aid of something like Round-up and a massive amount of time spent on supervising the problem so it doesn't return.

Two examples...

Five miles up the road a neighbour finally decided to tackle the green goutweed (gg) four years ago by cutting it right to the ground, then placing a black cloth weed barrier, and on top of that placing a heavy mulch of wood chips one foot thick. The cloth was overlapped by 6 inches where it met. This area was on his front lawn, an area about 30 feet by 100 feet.

Next year the gg started coming up where the cloth had been overlapped! You could see the rows. He uncovered the whole thing and this time placed 3 thicknesses of weed barrier and covered again with the mulch.

Forward to this year - it's back! EVERYWHERE!

Example #2

Neighbour a few houses down let this pretty ground cover grow under her trees. Then it started taking over the lawn. They have a walkway which is poured cement leading to their house. It is 4 feet wide, not sure how deep. That's the only thing which is stopping it from invading the other side of the property for now. She also meticulously deadheads all flowers so there are no seeds.

Don't waste your time. Go for the Round-up. I'm usually not so aggressive about plants, but this one and Japanese Knotweed and Purple Loosestrife are big problems and I invest too must time in my gardens to even consider being nice to these thugs.

I agree, be vicious!!! Even with roundup you may have to go to the extreme of covering it and mulching to try to choke out survivors. It should be outlawed. Can't believe they still sell the stuff.

I also suggest installing an edger temporarily to contain invasive roots. Do not attempt to pull out the plant lest you inadvertently create more new plants. Use roundup and allow the herbicide to trickle down to the very roots. Then mulch heavily.

When using roundup on aegopodium the best results occur on new growth. Use a string trimmer (it is the easiest)-cut the aegopodium to the ground. Wait for the new growth then apply the roundup. It will not eradicate completely but kills it quicker than applying to mature growth. Good luck.

I put down weed barrier and 2 inches of river rock and it still came back! Get tough.

Our neighbour had a flourishing garden of goutweed and when we moved in, we were dismayed to find it marching right across our lawn and garden. We've been here five years, in an inner city neighbourhood of Toronto. We've controlled the goutweed by pulling it up, pullin it up and pulling it up some more. Then lots of mulch. We've planted some tall plants like cupplant that shade out the goutweed and lots of ferns that do the same. It's not gone but a has retreated to the back corner of the lot where it comes up from behind the back neighbour's fence. Our neighbour to the south gave up on his back lawn, covered the whole thing with about three inches of cardboard and mulch on top of that. I bet when the mulch and cardboard break down we see goutweed again!

I thank you for your round up tips and will keep that in mind should the invader again push itself forward -- which wouldn't surprise me in the least.

By the way, I eat the goutweed. It's tasty and at least I get something out of this pest.

JD

Oh my, seeing this post reminds me that we have some (variegated) goutweed popping up in a spot that we painstakingly cleared of it over 10 years ago! At that time it was the main "garden" (along with chickweed) under a large conifer when we moved in, and there was a large patch in the back also. We went over every inch on our hands & knees, digging down with a hand fork as far as we could see roots, and taking all out that we could see.

In a couple of difficult spots (eg. hard inpenetrable soil or in between rocks/fence), we carefully painted a little bit of Roundup on to leaves that we bruised. Can't remember what we used to do that (that may have been the last time we used Roundup - but might be trying it again in a similar careful/limited fashion on a weed blackberry bush that is too difficult to get all out by hand digging).

Early on we had put some topsoil/compost mix on that area, then a few years later extended the garden by making a lasagna bed which also included that area to some extent. But I guess we left at least one little determined piece of root behind.

JD - interesting that it's edible! Wonder how the variegated version compares to the green for taste/edibility. Funny I actually like the looks of goutweed now more than then, so MAY pot some up (on concrete, and no letting flowers go to seed!!!)... bonus if it can be harvested for good eats.

I cleared out some property that I bought 3 years ago. This was heavy brush and cleared in the fall.

When I went back the next spring this is what I found. Very evil stuff.

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By mikeinparadise at 2008-08-01

At least it hid all the stumps...

I pulled all the stumps and tilled it and of course it came back.

Soooo I decided to try planting clover to see if it would smother out the goutweed. So far it is doing a good job but it needs to keep spreading. Not sure how it will work under the trees as I have not done that part yet.

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By mikeinparadise at 2008-08-01
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By mikeinparadise, shot with Canon PowerShot A20 at 2008-08-01

Of course this will only work for a lawn and then you end up with clover but I am liking the clover.

hi, I have goutweed in flower beds which I'm controlling (just) through digging and physical removal, but now it's spreading through my lawn. Will encouraging the growth of the grass control the goutweed, and what would be the best way to do this? Thanks

I know that it's been a few years since this post was written, but I just wanted to add a special note. Anyone who lives in eastern NA & thinks they have a problem with Goutweed may want to double-check they don't actually have Virginia Waterleaf (Hydrophyllum virginianum). It will naturalize quite quickly, especially in rural areas & looks similar to Goutweed. The flowers are very different between the two, though. Goutweed has a taller stalk with a Queen Anne's Lace-type flower, whereas Virginia Waterleaf has small clusters of drooping lavender, or white bell-shaped flowers.

I wanted to also add a picture of the leaves of Virginia Waterleaf (Hydrophyllum virginianum), a native of eastern NA. Young leaves can also have white markings that look like drops of water, or a slightly faded variegation. The leaves & spreading habits are very similar to Goutweed. Please see the post above for a picture of the flowers, which are quite different from the taller flower stalks of Goutweed.

Does variegated goutweed always turn to the nasty green stuff if it is not obsessively watched?

I've been fighting this Bishops Weed for years. I seem to have it under control in my flower beds with obsessive-compulsive hand pulling. Now it has gotten into my 100+ year old wisteria, fondly known as "Satan", and the two invasive evil demons of the plant kingdom are set to battle it out.

I've also had limited success killing large patches of the Bishops Weed surrounding a dry stone wall with a Borax paste.

We have it in our yard here in Finland. It grows everywhere here in Southern Finland, mostly on old homesteads and seems to thrive in even the worst soil. Previous home owners were only using the property occasionally over about a 13 year period and weren't doing anything to upkeep what had been a beautiful yard and garden. Goutweed is called "vuohenputki" here in Finland.

I've read numerous articles about eradication and can only add that it's a nuisance and difficult to get rid of. Last spring we cleared a bed of it by pulling up every piece we could find. Results were pretty good. This year only a few popped up and it was mostly due to the rhizome being tightly compacted next to tree bases, etc.

In some areas we recently used heavy-duty carton cardboard topped with 2 inches of topsoil which we intend to hand seed. No results yet on whether this will kill or impede the spread of the weed as we've only just done this.

Our latest concern is getting rid of the weed that is everywhere else in the yard. I am opposed to using Roundup, but after lamenting the use of it, I broke down after realizing we could never dig all of it up as it is nearly everywhere on our 3/4 acre property. Sadly, roundup did nothing.

Our next plan is to use a commercial grade polypropelene fiber fabric barrier.
We've ordered 800M which comes on a large spool. It isn't enough to cover the whole yard, but will go a long way in the nearest parts to the house.
We expect delivery of the barrier fabric in a week. Once we get it laid out, it too will get a topsoil cover then seeded.

I don't want to see goutweed or any other weed in my yard again. I can tell you that product-wise, equipment-wise, etc is much different here than in the US. I think trying to solve this problem would be difficult anywhere, but here it seems even more so with such limited availability of product that is so common place in the US. For instance weed-n-feed, miracle gro, etc. etc. none of which is sold here. Even finding a rotary push lawn spreader would take a long time to locate, if at all. :/

I have been successful in removing goutweed but only when it has been contained in a smaller area. One was a garden along the side of the house, the other was a larger area under some cedars. It took a few years of digging out the roots as far down as I could, of spraying it with weed killer (I really hate using this stuff because it is deadly for pollinators) when the plant was first emerging in spring, and removing every single piece, no matter how small, of root, leaf or blossom. I also have it on a slope in the front of our house, in full sun, and it is the most awful, aggressive plant I have ever dealt with. The area is about 70 feet long and 15 feet wide and every year three or four times we have to dig along the full 70 feet at the top of the slope where it meets the main garden and pull it out so it stays out of the rest of the garden. And deadheading the horrid blooms as well. This stuff should be banned. I curse the former owners of the house who planted it every time I look at it. I do a lot of cursing. I am about to tackle another smaller area using boiling water to try and kill it after I have cut it down to almost ground level. I hate wasting water on it but it's that or weed killer.

I would like to add that I've had some success in grassy areas I can cut the goutweed with the lanwmower.

It really never re-established in the main parts of the grassy lawn. Only places it still poses problems are areas that are on the fringe of the property. Along fences, rockeries, base of trees, etc. Occassionaly, there will be a few leaves emerging within a bed, but those are hand-pulled out pretty quickly.

Goutweed is horrible stuff. I know the agony of dealing with it first-hand. Everyone still battling with it, you have my sympathies!