roundup can kill grass and any residuals will continue to kill off new grass. If this is as deep rooted as you described, you may need more roundup to get rid of the problem.

I would consider digging up the patch of lawn with the ajuga problem and replacing the gaps with new sod. It will probably end costing less than the roundup.

Thanks.

Yes, I do have some concern about residual roundup, that's why I thought painting the leaves (after clipping surrounding grass) might be better than spot spraying. Maybe also spray with a little dish soap solution beforehand to aid absorption. Surely, if I take that approach and it works, there should be little if any residual in the soil, providing I dig the dead plants up before seeding. Does glyphosate also leach from the (dying) plant into the soil?

Assuming it took around 10 days to kill it, that would leave about 3 weeks before I plan to over-seed. Should I maybe leave it longer?

I have thought about replacing with sod. But again I'm worried that any digging in and around the patch (until the ajuga is completely dead) risks leaving viable runner fragments.

Ironically, this problem seemed to arise after we put some of the black plastic border down around the garden bed last summer. Although the border is 4" deep, I can easily see how the ajuta roots/runners could pass under that. Also, I suspect that when digging the trough for the border and then replacing bits of sod to fill the gap, cut off fragments of the ajuta stems probably got pressed into the soil.

But, who knows, it might have spread anyway. As I said, the lawn hasn't exactly been in top form for the past year or so.

There doesn't appear to be a firm no. of days that the herbicide can remain in the soil. In some areas is was 3 days and in other areas more than 100 days... all depends on the soil and also the concentration.

Have you tried using vinegar and water on the plants? This can kill but maybe just a bit slower.

In about 3 weeks, you'd be so close to Sept(cooler month) that you can probably just wait it out and reseed your lawn instead of adding new sod.

I do have ajuga in my garden bed too but it's prevented from invading the grass area by a deep & wide trench filled with river rocks. I could easily dig out any plant that strayed the 'zone'.

Yes, I've read that a vinegar-dish soap mix (some people add salt) is quite effective, and rapid, in killing top growth but I don't think it penetrates the runner/root system well.

I was wondering whether a Triclopyr-based product used for treating 'creeping weeds' (Ortho Weed-B-Gon Chickweed-Clover-Oxalis Killer or similar) might be effective. I've also got a fair amount of Ground Ivy (Creeping Charlie) and Yellow Trefoil due to the wet summer this year, and poor lawn condition. However, all such herbicides are banned in Canada for residential use, and I doubt the regular iron-based Weed-B-Gon that is available would be much use.

So, I've set up some tests with the Roundup.

On a couple patches, I snipped away the grass around the ajuga, tore some of the leaves and sprayed with Dawn soap. Let that just dry and then carefully painted Roundup (regular strength 50ml conc/Liter water) onto the leaves. Pre-spraying with soap definitely helps to avoid the Roundup beading up and running off the leaves. A bit tedious, but we'll see how it goes.

Some isolated plants (well out into the lawn) I carefully dug up leaving the roots and runner (stolon) attached. Slipped a slotted piece of card under the lifted plant, sprayed with the soap and painted Roundup onto the leaves, roots and exposed stolon. The card served to keep the Roundup off the surrounding grass.

For one, quite dense patch, close to the border, I completely dug up the turf, plus a couple of inches of sub-soil to an area of at at least 6 inches around the patch and right up to the border - around 7-8 sq ft in total. Doused the 'pit' with some hot soapy water and covered with black plastic until I decide whether to seed or put some turf in - the municipality are laying turf in a local park and I'm thinking to ask them for a bit.

Needless to say, the wife was rather perturbed by my bizarre actions - and telling her I'd become a 'landscape artist' drew no laughs - but what can you do.

Yes, I can see how a wide/deep trench filled with river stone would help - maybe even stone dust with some gravel on top. For now, I've pulled the ajuga up a few inches back from the border and wiped Roundup on the exposed stolons and root stumps. Hope it doesn't destroy too much....or do I??

This post was edited by WorBry on Tue, Aug 6, 13 at 13:53

To be honest, I avoid pesticides and herbicides as much as I can. I've heard of certain pesticides/herbicides that remain in the system for years. Salt is especially not good for areas you intend to grow plants. salts kill any plants regardless if these are weeds or grass.

If large patches or ajuga exists and it really bothers you that much.. try smothering them by blocking off their access to sunlight. Some have used black plastic to do the job.. some in trying to convert a lawn into a bed, would place thick layers of paper and then topped them off with soil. The paper eventually rots away or is eaten by earthworms while the soil on top allows for one to plant immediately. A cheaters way to make new beds. Anyway the trick is blocking off sunlight.

To be honest, I avoid pesticides and herbicides as much as I can. I've heard of certain pesticides/herbicides that remain in the system for years. Salt is especially not good for areas you intend to grow plants. salts kill any plants regardless if these are weeds or grass.

If large patches or ajuga exists and it really bothers you that much.. try smothering them by blocking off their access to sunlight. Some have used black plastic to do the job.. some in trying to convert a lawn into a bed, would place thick layers of paper and then topped them off with soil. The paper eventually rots away or is eaten by earthworms while the soil on top allows for one to plant immediately. A cheaters way to make new beds. Anyway the trick is blocking off sunlight.

You will win with your round up regime. Just be dedicated hitting any new growth. It might take a season or two as rhizomes and stolons can live a while under the ground.

Glyphosate does get down and kill the rhizome and stolons. It is a contact killer and has no residual effect. That is how farmers are able to spray for weeds then direct seed on top. Glyphosate also breaks down rather quickly in the soil. If your not sure you can phone the number on the bottle :)

I wonder about the long term effect of using hot water. Many species of plants that spread by rhizome can survive forest fires. It may appear to kill them that year but they come right back the next.

I also would be interested in how plastic works. Will the rhizome pokes up see no light then travel farther? How far before it runs out of energy and dies? I haven't dealt with ajuga but have seen rhizomes on other plants go up around 5'. I am curious to your results.

Good luck and keep us informed.

SCG

Thanks both.

Well, after 3 days all the plants I 'painted' with Roundup are starting to go. Those that I up lifted are shriveled already (as you'd expect), but I'm leaving them there just to see if the glyphosate does indeed progress down the attached stolon.

No, I don't really like using herbicides either, but I need to get this cleared up before early fall aeration and over-seeding. The lawn badly needs it and in previous seasons of patching white grub damage I've tended to seed too late to get the turf well established before first frost, and boy do those grubs love young grass roots.

I could maybe try the plastic smothering approach if the ajuga rears it's head in the future.

The dousing of the 'dug up' patch with hot soapy water was really just for good measure. I'm pretty sure (hoping) I got everything up. I looked carefully when I was lifting the sod.

Talking about plants with rhizomes. I've now discovered that a strip of lawn between my driveway and the neighbors is riddled with (Field) Horsetail. Thought it was some KBG coming up until I had a closer look. Some of it appears to be dieing back (blackening around the base stems) but in other wetter areas it's flourishing. From what I've read the 'fertile' stems are superseded by 'sterile' vegetative stems, that are distinguished by little leaflets on the stem whirls. That's what I'm seeing.

The surface growth pulls up easy enough, but from what I've read, it's very difficult, if not impossible to eradicate, as the rhizomes and tubers can go several meters underground, and even if one manages to locate and sever sub-surface roots, it just grows back with avengence. Can't be sure of the source, but in and around the neighbors rockery they've let it over grow to large mature plants, some with spore pods. Oh, boy. Seems the only approach for lawn control is maintaining thick turf, frequent mowing, good drainage, aeration and liming if the soil is on the acid side. All the more reason why I need to get a good start on the over-seeding. Kind of twitchy about core aerating that strip though, as, by all accounts, viable rhizome fragments are easily spread.

Sometimes ignorance is bliss.

I must say, I was tempted to nuke the strip with Round-up, as it's full of other weeds also (dense Crabgrass for one), with just a few areas of established and patched new grass. I know the Crabgrass will die off by first frost, but I don't really want to leave the over-seeding too late. And now I'm worried that even raking over the area will spread surviving sub-surface Horsetail rhizome fragments.

Off the original topic, I know, but any suggestions on the best possible line of attack.

Edit: Tested the soil pH and it looks to be around 7.0. Is it still maybe worth liming a little to hopefully to try and accelerate die-back of the Horsetail and then over-seed the exposed patches in compost? Still leaves a problem with the crabgrass areas though. I had been thinking to heavily core aerate those areas and seed into the holes, but this horsetail issue now puts me off doing any aeration on this strip.

This post was edited by WorBry on Thu, Aug 8, 13 at 0:37

Yeah, sometimes ignorance is bliss LOL

I prefer not to use herbicides either but when it comes to invasive plants sometimes it is pretty much the only way.

My only concern with black plastic would be how big of an area that you would have to cover and how long would you have to leave it. I would imagine you would want to cover an area at least a couple meters bigger than what you see. I also can't find any information on how long ajuga rhizomes and stolons can survive underground. I know some plants can live over a year. I'd venture a guess you would have to cover it for at least one full growing season, two to be safe.

The alternative to black plastic would to diligently clip the leaves off as you see them appear. This too would rob the plant of the ability to produce food. BUT the unknown portion of that would be if the tiny leaves produce enough food to sustain the plant before you get to clipping them.

I have no experience with horsetail to be able to help you and I would have to rely on the web research. The little I have done looks like your in for a fight for a few years. Also looks like aeration would be more beneficial than detrimental.

Good luck and keep us informed

SCG

Progress report on the "Ajuga treatment" exercise.

Well, after 9 days of Roundup treatment. On the plus side:

The small isolated plants that I lifted have all rotted and the Roundup does appear to be working, albeit slowly, on the exposed root nodes and stolons - turning woody. I'll leave as is for now, and maybe excavate in a couple of weeks to see if the glyphosate has progressed down the stolons underground.

As for the patches that I treated, without any excavation. The clumps with young small leaf heads have, by now, either perished or are in the final throws. Those with larger, mature leaves however have proved a bit more resilient - appear to wilt and fade a bit at first but then just stay like that. Probably a combination of having a tougher cuticle to penetrate and the fact that they are slower growing - glyphosate needs actively growing tissue to act. So, after 5 days, I did a repeat application with a doubled-concentration of the Roundup (100ml concentrate/Liter) and it appears to have sped up the process a bit. I think this will take some time though, and maybe further applications.

On the down-side:

Before considering using Roundup, I had in my ignorance, tried making a line of deep spade cuts about 6 inches out from the border, thinking that severing all of the runners from the garden bed would help to prevent further spread. Did the same around one of the patches. BIG MISTAKE. After a 7 day stretch of dry weather, we've just had 2 nights with rain. And wouldn't you know it. New clusters of small Ajuga leaves are now starting to sprout up right along the line where I made the cuts, and most annoyingly in areas that I had re-seeded only a few weeks before. Evidently, the severed end of the runners had just regrown and pushed up to the surface. So, now, more clumps to treat, and I might as well just spot spray them as it is impossible to paint the tiny leaves, without killing off the surrounding new grass. So lessons learned. Chopping around this stuff only makes matters worse.

As for the patch where I completely removed the sod. Well, I haven't done anything with it yet. Still covered with plastic sheet. Inspected it yesterday and can't see anything sprouting from the 'pit' bed. But, on the edge that meets the garden bed, I can see a few runners already growing out from under the black border barrier. I suspect that if left untreated, these runners would grow out along the floor of the covered pit in search of light and sooner or later little ajuga plants would start to appear around the section. So, I think it would pay to spray that edge with Roundup to stunt any outgrowth from the garden bed. Just glad I hadn't re-seeded the patch or laid fresh turf.

So, both progress and lessons learned. What remains to be seen is whether Roundup, after killing surface growth, does indeed go on to kill the tougher stolons underground, at least to a depth that allows preparation of the soil for re-seeding without fear of breaking up viable fragments.

Also, although pre-spraying with detergent/soap does seem to help glyphosate penetration, I'm wondering if there is something better. From what I've read, agricultural formulations of glyphosate work most efficiently with non-ionic surfactants in breaking down the waxy cuticle of tougher herbaceous vegetation, but I doubt these proprietary adjuvants are available to the general public.

I do see that that there is a Roundup formulation specifically intended for tough invasive vegetation - "Roundup Poison Ivy Plus Tough Brush Killer":

http://www.scotts.ca/smg/brand/roundup/stoppoisonivy/

Contains both glyphosate and triclopyr and claims to be "Strong enough to penetrate the tough, waxy leaves of poison ivy, poison oak, poison sumac, blackberries, kudzu, and other hard-to-control invasive weeds". Just what specific ingredient aids penetration it would be interesting to know. The MSDS info doesn't specify. But of course, containing triclopyr, it is not available in Canada anyway.

So, I'll just have to persevere with the regular stuff.

Man, this is turning into a nightmare. Now, that I've become sensitized to spotting ajuga, I've now discovered it in a couple of areas at the back of the house - thankfully not yet in the lawn.

One, in a bed right at the bottom of the garden. I was clearing a patch of mint that was spreading in from the neighbors, and there were patches of Ajuga mixed in with it. Couldn't see any planted on the neighbors side. I can't believe it could have spread all that way (50 meters or so) round from the front of the house by runners, not without popping up on the way. Only thing I can think of is that bed backs onto a strip of wooded area where we usually dump clippings etc. and I'll bet dumped/trailed Ajuga fragments took root there and spread down. I know they are in the same plant family, but it's definitely Ajuga, not sprouting mint. Needless to say, out came the Roundup.

And then there's another small isolated patch of Ajuga in a flower bed just behind the house close to the deck. Had a good look under and around the deck and can't see anywhere else. So, how on earth could it get there. I'm wondering if maybe fragments got spread by garden tools in the annual trim-back/rake-over last autumn.

I think this could get me paranoid and obsessive about cleaning the mower and tools after use.

Sorry, I forgot which forums I go to sometimes.

I can't remember and too lazy to read back but were you the one that planted the ajuga or did you inherit it?

I sometimes use full strength roundup in a sponge pen. Doesn't take much of a dab to do the trick and works nicely on very small leaves.

From what I have read glyphosate will make it done to the stolon and it makes sense, its in the system. I am not sure if it kills the stolon but since it affects the enzyme that allows the plant to grow the stolon, eventually, will die.

I know farmers that still use regular roundup but they mix liquid dish soap with it. You can also scuff waxy plants for better penetration. I like to mow or weed wack before spraying. I think the open cut speeds things up.

I guess it is quite plausible that you could have raked up a stolon and transplanted it at another location. I highly doubt it spread via clippings.

After your experience I am applying round up to the one in my garden. It is a young plant so I hope it dies fast.

IMHO I think I would just reseed or place sod and be diligent in applying roundup to anything that pops up. If this invasive plant is like others it could take years to eradicate, sorry.

Good luck

SCG

We inherited the Ajuga-planted garden bed with the house. For sure, knowing what I know now, I would never have planted it, at least not next to a lawn and with no effective barrier.

That said, I can't recall it being a noticeable problem the first two years, despite there being no border barrier. But at that time, the lawn was in quite good condition. As I mentioned before, these clumps first started to become conspicuous last autumn, after the wife put some of the flexible black border stuff in, for appearance more than anything else. Seems obvious now that, in the process of digging the trench, stolons at the edge got broken up, and then in back-filling the trench with the dug-out turf clods more stolon fragments got pressed in. These stolon fragments sprouted and spread. And then this year, with the wet spring and summer, plus the poor condition of the lawn and my earlier attempts at digging the ajuga clumps up and re-seeding, it went rampant.

Had I laid the border myself, I probably would have dug the border trench a bit deeper (6" or so), set the barrier on a few inches of stone dust, wrapped landscape fabric under and up both sides of the barrier and back-filled the trench on the lawn side with stone dust, giving a few inches margin. That's how I usually do borders, but mainly to help with drainage (sometimes drill holes in the barrier) and make mowing and edge weeding easier. But, as discussed earlier, I doubt it would have made a difference, as, from what I've seen, the Ajuga stolons can easily get under 4" of bordering.

As I mentioned, I have cut back the ajuga on the bed side a bit and painted Roundup onto the exposed stolons and root clumps, with the hope that that will help to stop further spread. Short of pulling up the border and re-doing it (and risking further spread in the process), the only additional measure I can think of would be to (try and) hammer in a strip of corrugated sheeting (say 9-12" deep) along side the border, maybe spraying Roundup on both sides as I do it. Could be tricky.

One other thing I've read is that Ajuga stolons do not normally exceed 12" in length between 'mother' and 'daughter' plants. So, when an isolated Ajuga plant is found (as in my case) way out (10' or more) into the lawn, with no obvious chain of clumps leading to it, it likely that it has arisen from a stray stolon fragment that has taken root. The other thing to watch for is that around that little clump (effectively a new 'mother' plant) stolons could already have sprouted and are in the process of generating several daughter plants. And this I have observed. Carefully painted Roundup on the leaves and then, while waiting for something to happen, find tiny plants cropping up around it. Obviously, it takes a while for the glyphosate growth inhibition to kick in.

So I'm tending to veer from the careful 'painting' of individual plants that I started with, to spraying a patch or clump, and then using a paint brush to bristle in the Roundup, so that it reaches any tiny plants that maybe emerging. Sure, it kills the grass, but by the time you've painted each new plant head that comes up in a patch (assuming you can remember each one you've treated - tried using food coloring as a marker - useless) you might as well have sprayed the area. Plus, killing the surrounding grass allows you to see more easily the network of connecting stolons. That's the point I'm at right now. On some of the patches the leaves have shriveled and it is reasonable to assume that the nodal roots are dead also. It does look as if the inter-connecting stolons are dying also (turning woody) but that is taking longer. Which seems reasonable; as you stated, stolons (as modified stems) are part of the living plant system and vascularized. Apparently, in some 'stolonized plants' inter-connecting stolons do disintegrate naturally over a period of time, but in others (like strawberries) they continue to provide exchange between plants in the same clone - sharing root systems etc. Not sure about Ajuga, but I'm wondering if that's why small daughter plants seem to crop up shortly after applying Roundup to the leaves of an isolated mother plant. Does maybe 'injury' release transmitters that stimulate rapid growth of emerging daughter plants - a kind of adaptive survival reaction? That said, in an established clone with mature connecting stolons, one would not expect there to be many, if any, nodal growing points remaining. Plus, destroying the roots stops the release of hormones that normally stimulate the stolon to put up leafy stems. So the action of Roundup will be limited to inhibiting the basal regenerative processes that keep the stolon alive, rather than active new growth. As a result, the killing will be much slower.

To what extent glyphosate might be absorbed through the stolon wall, I'm not sure. I've tried cutting some of them and applying a little more Roundup to the ends to see if that speeds things up.

One things for sure, I'm not digging anything up until I'm convinced that it's all dead.

Haven't tried undiluted Roundup. The 'twice regular strength' seems to be working OK.

I've also read that it helps to keep the treated area moist, which makes sense. Glyphosate works most efficiently on actively growing plants, and, whilst it's nice to see a plant shrivel up, premature dessication actually retards the killing process.That's why I think alternative methods like vinegar-soap which basically burn and dry up the surface growth are probably counter-productive in the long run. Best to keep the plant system intact while the glyphosate does its work, even if that takes time.

Cheers.

This post was edited by WorBry on Sun, Aug 18, 13 at 11:59

Good information on the ajuga stolon length. I hope I don't have to ever need it.

I talked to the fellow that owns the nursery I go to and he said that they have found the stolons above the soil line in grass. He figures this is how it often gets transplanted as it is raked up. They won't stock it on the shelves anymore and unless it is custom ordered they won't sell it.

I like your idea of nuking areas you find it. I wasn't sure you wanted to go to that length but at the end of the day it will be the fastest and most thorough way.

You know, one thing that we have really overlooked is that ajuga is a broadleaf plant so you should be able to kill it with 2,4-D (killex or the like). Might be worth a try on the borders to save a little grass.

I haven't treated mine with roundup yet so I can try killex on it. I'll get on it after this post and get back to you.

Okay sprayed...will update when I see progress.

SCG

Can't get 2,4-D products for residential use in Canada either. Not sure what the turf maintenance firms (and cowboys) spray as herbicide around here. They are very cagey. Most tell you it's 'fertilizer' or that they are just 'watering'.....whilst wearing a protective suit and mask....damn toxic that H2O. One sort of nodded when I queried Dicamba.

You may not be able to get killex locally due to local or provincial bylaws but you certainly can get it. If you can not get it we can figure a way for me to ship you some.

Commercial companies fall under different rules in many places.

SCG

After one day the ajuga is showing signs.... 2,4-D works

Sounds encouraging. I'd read some mixed reports on the effectiveness of 2,4-D (alone) against Ajuga, but (possibly) better results with a 3-way product, which Killex is (2,4-D, Mecoprop-P, Dicamba)

http://forums2.gardenweb.com/forums/load/lawns/msg0918365630041.html

http://www.lawnsite.com/showthread.php?t=276043

So, it will be interesting to see your results.

Yes, you are right Killex is available (at Canadian Tire), but only in British Columbia, Alberta & Manitoba. You are in BC, right? I'm in QC...sigh. Kind of farcical really, this provincial herbicide 'ban', when commercial lawn care companies can readily get the stuff (and political parties also). At least a third of the residents on my estate have their lawns sprayed....whether they really need it or not. I reckon the previous owner of my house was one and that chemical-dependency was at least part of the reason for my lawn problems....all those dormant seeds. That's my excuse anyway.

Anyhow, I'll persist with the Roundup (no other choice now). Whilst slow (it's been about 2 1/2 weeks) it does appear to be working. Probably would have been quicker if I'd sprayed affected areas, rather than leaf-painted, from the start. Seems kind of counter-intuitive to water the weeds, but keeping the treated areas moist definitely helps.

So, at the current rate of progress I'm still hoping that I'll be able to over-seed by mid-September. The thing that concerns me though is the sheer number and variety of weeds that are still coming up. Sure, the best natural weed-defense is a thick turf, but I'm beginning to think that I really do need to tackle at least the perennial broad-leafs, and if possible the dense carpets of crabgrass, which are now starting to turn to seed. The white clover that is taking over some areas I can live with. In fact I'm not averse to the idea of a mixed grass-clover lawn, though I can't speak for the neighbors. But the black medic (yellow trefoil) that is prevalent on my front lawn is less desirable.

As someone commented on another forum - organic living is all well and good but sometimes you need a prescription from the doctor.

I have inquired whether one the lawn-care firms (the one that acknowledged they use herbicides) might do a one-off spray, but they are only interested in offering a 'full year' maintenance plan.

There's no way I could manually pull all of this stuff, as adept as I am with a Weed-Hound, and a lot of it is now partially obscured by crabgrass and clover/black medic.

So, I guess I could try the available iron-based Weed-B-Gon, several neighbors look like they are having some success, at least with spot sprayed dandelions, but I think I'd need a bit more than spot treatment. Or else see if I can get hold of some Killex (might come back you). The big question then is how much treatment at this stage would put back fall over-seeding (killing time plus soil residual to consider). Don't really want to wait until Spring, as I'd like to try and get an early start with a pre-emergent then.

What to do?

This post was edited by WorBry on Tue, Aug 20, 13 at 14:11

I have never noticed a residual effect with killlex and have seeded shortly after. Once my lawns get established I only have to spray every few years.

Let me know if you need anything.

Tell the yard company you want to start yearly maintenance. They can finish this year and bill you then start again next year.

SCG

Update

My ajuga is toast. Not even compost worthy. No runners nothing in the past month.

Hope you have similar results.

SCG

Strange....my first submitted reply hasn't appeared, so here it is again in a nutshell.

The isolated patches of ajuga, that likely arose from distributed stolon fragments are good and dead, but the lawn areas I treated with Roundup next to the garden bed border are a different story. Despite repeated spray treatments, small new ajuga plants have continued to emerge and so I suspect the Roundup, whilst effective in killing the plant heads and sub-surface root system, is not potent enough to progress down to mature runners deeper down, which have sprouted up to generate new plants. So, I'm left with the prospect of digging up the sod to expose these deeper stolons and hope that spraying the severed ends puts a stop to it. Nothing has re-appeared on the one patch that I dug up at an earlier stage, so I'm hopeful that will work.

Of course, with hindsight I could have saved time, and Roundup, in doing that in the first place, but who knew?

Glad Killex worked for you.

Cheers.

I'd be inclined to think the new sprouts are new and from untreated stolons. Unfortunately my computer is in the shop or I could show you an amazing pic I was sent of how many rhizomes they can send out. I believe your going to see it for a few years, sorry.

SCG