We're into our 4th year of Japanese knotweed eradication; we started the year we bought this place. No herbicides were used. My wife played the role of excavator. Bless her heart, she dug more than I could have imagined at the beginning. We knew it was not going to end the stuff but we decided to get as many rhizomes as possible. Our Knotweed was in a section where filled land transitioned about 8' down to the natural ground level. The patch is shaded well so not much else grows back there. It is 140' long and 30' wide. The fill work was done in the 1970's. I don't know if the knotweed started then or sometime later. Year 2 we finished the excavation including a trench all around it to establish a boundary. We double tarped the trench and backfilled to level. Then the entire area was tarped. We taped all of the seams. All told we had two pickup loads of rhizomes and crowns. We bagged and sent them to the landfill. Year 3: The knotweed has now had almost no sunshine for 2 years. We rolled back the tarps and found the most vital remaining rhizomes and dug them out....replaced the tarps and remained vigilant, digging out any new sprouts around the area. We've only found a handful...but just ONE is too many. This was year 4: We rolled the tarp ack and found very little regrowth after 3 years with no sunlight. We covered the entire area with another very heavy duty tarp. Next year is year 5 and we'll be adding a layer of bark mulch. We didn't want to do that in case we had to back-track....because this stuff is unbelievably resilient. We only found two stray sprouts this year...feeling pretty good about it so far.

I have a camphor tree that I cut down leaving a small 10" diameter trunk. Will this work for it? Camphors are a real pain! Thank you your time and the video!

How do i avoid mowing it when its all over the middle of the lawn?

One of the most useful descriptions of a doable plan for removing this nasty weed. Thank you!

Same chemical used in roundup. It causes cancers and there are tons of lawsuits. Please don't use these chemicals. They're are only allowed because of paid lobbiests keeping harmful chemicals legal.There are lots of different things to use. I use softener salt sitting in a bucket of water for a couple of days then pour in a garden sprayer. It kills weeds and they dont grow back for months. Remember we are all drinking the water these chemicals seep into.

glyphosate is illegal in most countries by now....

Excellent instruction. I have 1/2 my backyard proper, plus along the creek in the back and side of my property. I'll be injecting glyphosate directly. I noticed you said to inject into the core. However, I also heard of injecting into the phloem. What is your take on this? I'm purchasing glyphosate this next month (August 2024). One quart (5 ml each) covers approx 183 stalks. I'm using a 10% waste coverage (approx 175 stalks). Thank you for the excellent presentation.

I have this thing about 6m2 at my property in Ontario and just found out what this nuts thing is. I Dug it out this weekend hard with pick and followed the roots going and what I found interesting, it nested below concrete stairs fundaments.I am south Europen and this thing have the Same rooting as a fig tree.Exactly the same but way more invasive. They like wet concrete or stone deep underneath. Wet and safe from anything. It is impossible to kill it without removing the base of the concrete where the root Is hiding. Luckily I bough this property after fire destroyed and that fundaments will be gone. Just my experience. I will treat with herbicide in the fall and keep you posted. All the dug out roots I will burn in the metal barrel, bit by bit. What a crazy plant.

I can’t imagine a worse video to keep me from buying this system.

At first you mention the two herbicides but the rest of the video it's all of sudden some kind of green foam??

Will this stuff kill a tree if applied to one or two of its roots?

Japanese knottweed gets rid of lyme disease

If you cut the tree down, you can drill series of vertical holes around the edge of the stump right next to the bark and pour weedkiller into them. Cover with plastic sheet to keep rain off and prevent stump from drying out. Top up regularly over the next few days.

Hi, I have a large oak tree (1m circumference) . How long will it take for this tree to die after doing one of these methods, any recommendations? Will the tree fall by itself as soon as it’s dead, or will it die and keep standing? It is quite top heavy. How do we know when it’s dead, and if it is about to fall by itself, how do we know this is likely to happen soon?

At 5:50: & at 10:13 important info! Wait to trwat until aft knotweed has flowered (fall, but b4 a killing frost)

Very informative video. Thanks for posting this. ❤

Trying to rescue 3 massive oaks from very mature Ivy. Ring cut them, the English is almost ready to rot off, leaves are falling. This other stuff I don't recognize, bushy stuff, not poison, it rings the tree all the way up with 6 to 8 feet of bush. Some of its base were 6 and 8 inch around, cut about 10 on the one tree. Been a few weeks and it's still shiny green. I may shoot a line if I can find a safe crotch. Just can't distinguish to be certain of life from the ground as bushy as it is.

Hi, could you please recommend, how to get rid of Giant Grass Canes with glyposate safely for stray animals, if i cant fence canes, or isolate animals. I wonder if cutting down canes close to soil level, pour little amount of herbicide into cane, then cover all cut area with cut down cane mass will protect animals nearby ? Who might walk the treated area.

This is so interesting. I think the general public assumes since vinegar and salt are known/common household entities, they’re automatically safer weed killers than the “chemical” glycosate. (Regardless of efficacy). Paying attention in Bio 101 would’ve taught us that even dihydrogen monoxide is a “chemical” and we freely drink and bathe in it. lol. Also the basic definition of “organic” meaning carbon-containing, not just synonymous with more expensive groceries. I’m sure I’m preaching to the choir, though…living in the rural US with a science background can be frustrating lol. Anyway, I used Ortho Ground clear last year on the weeds coming up from the end of my driveway and walkway/porch(imapyzr primarily) and it worked pretty well. There’s a lot of feral cats that hang out around my property though, and while I don’t think they eat the weeds, they might hunt prey that feed on the weeds-What would you recommend in this case? I think It’s mostly purslane, dandelion, curly dock, and plantain. The ground clear worked last year, but pretty much everything re-grew with a vengeance. You think targeted RoundUp would have the least ecological impact? Thanks!

I have been pulling and cutting my knotweed last year and this year so far. I am just discovering your page and decide that herbicides are a good idea. The knotweed starts at the front of my property and goes all the way back, it’s goes about the length of a basketball court and is probably 5 feet wide. It’s a lot of knotweed. It’s also growing on a very steep hill. I stopped pulling the knotweed a few days ago, should I let it continue to grow until this fall and then try the injection method? We are very close to our neighbor and her garden so I want to try and keep the herbicides contained as much as possible. I feel comfortable injecting the bigger stalks, but what do you recommend I do with the small stalks that are too small to inject that won’t spread herbicides everywhere?

at about the 8:00 minute mark, you mentioned Tim Miller from Washington State U. wiped plant with three herbicides, including glyphosate--what were the other two (you glossed over them)? thanks

Thoughts on adding ammonium sulfate ( kzfaq.info/get/bejne/l9F5iZCrptqbhoU.htmlsi=FWfl-0dukTQmf4Vf ) to the mix for the foliar application?

Use Glyphosate, (never use RoundUp brand). 2 ounces per gallon, 1 ounce of a sticker/adjuvant. Cover all surfaces of the plant. The silver bullet is to wait for the herbicide to be absorbed and then SPRAY IT A SECOND TIME! This is the only way to get 90 - 100% die-off in one season's treatment. DO NOT SPRAY NEAR ANY WATER. If growing beside water use the cut stem application. The most optimal month to treat knotweed is in September after the blooms and bees are gone!!!

Hey, I’m about to tackle my knotweed invasion. My question is: the plants are alrdy really talk and bushy. Shall I cut them down now so I can treat them more effective in fall? Maybe burn the cut sticks in a big fire pit or shall I just let it grow until fall? It’s alrdy way taller than I am. Thank you in advance. Also will it damage my Peach tree next to the knotweed with the foam? Really appreciate your knowledge.

How to kill tree roots: spray this foam to stop the stump growing. On our next episode, also titled “How to kill roots”, we'll show you how to tie a daisy to an elephant.

Most informative. I had read or seen the info about late summer application 2 years ago, and hit our stands in late September, just once, with a very strong mix of glyphosate and a large sprayer, on a calm morning. Unfortunately the sprayer got damaged so it didn't get done last year. But the single application was quite effective last year. This spring I am seeing a few plants coming up, so will follow the same approach this fall. The largest area is on a near 2 to 1 slope, so I don't know what natives can work there.

Hi John--thank you for all this information. We are dealing with huge swaths of knotweed on a property we bought at the end of 2022. Last fall we applied glyphosate to a portion of it, and it was fairly successful. This year we will use your kit and try to hit it twice, and tackle more of it. I know you say not to cut, but it's June 1 and much of it is already over 5 feet tall. By fall, even if we create paths within the swaths, we won't be able to get anywhere near the tops of the plants for foliar spraying. Would it make sense to cut it now just to create shorter plants for fall? They'd be huge again by then, but maybe slightly more manageable for spraying... (Also, I don't think treating the stems is an option for us--there's simply too much. Spraying is probably our only hope.)

or just allow the deer in. my deer here in n. idaho eat them and keep them from getting out of hand.

I tried something similar to this method, and it made matters worse. Also, glyphosates are illegal for non-professional use in most countries. The experts I've talked to all say the same: Don't "disturb" knotweed, it will only make it spread more. The only thing to do right now (2024) is to wait for effective methods to be developed.

I got rid of all my knotweed, dug it up, and burnt it all up. It still came back, but just a few shots, just kept poisoning it. After 3 years, it was finally gone.

We recently found some of these sprouting in our yard and started freaking out... at max, they are 1-3 feet tall but a lot of them are inches/sprouting. What is the recommended treatment for these? Foam or foliar application? We haven't dug anything and are just a little confused about what to do right now since a lot of the advice seems to be for full-grown patches.

I have a field of young black locust treescoming up fast in the path that I will need to get to our huge stand of japanese knotweed later in the season. I have not had success killing it last year with the same foam treatment I use for the knotweed, however, I mixed your foam with triclopyr and water in one of the foam dispensers. It worked good, but I gummed-up my foam dispenser. Sadly, I didn't keep a journal of the concentration I used. The spray ticlopyr I'm using right now is just beading off the leaves, so I'm probably doing more harm than good in even trying so I gave up. I will be purchasing more of the blue foam dispensers anyway for this year's knotweed (it seems to have the best outcome of all the methods we tried), but can you please tell me, or direct me to where I can find a formula where I can mix triclopyr, foam, and water using your foam dispenser, so I can paint the leaves instead? There's so many and so dense that I can't let them occlude our path to the knotweed. Thanks so much in advance if you can help.

Hi sir! Thank you for your amazing video. This was the most well done and most informative I’ve come across about excavation of knotweed. I am finally going to tackle our knotweed infestation and it is late spring going into summer. I have not done any treatment and I have an area of knotweeds surrounded by vine thorns and all kind of plants. Due to the surrounding plants/spiky vines, the use of weed wacker is necessary to get to the knotweeds. Once I clear the area and am able to get the the stem. I will treat it with herbicide and wait for next year and excavate every knotweed. Is this the way to go?

Nice and informative video. Now I know much better how to go from here, but it will not be an easy task. Late last fall we started to pull down a lot of JKW (a little part next to a road, that unfortenately belongs to our land - a bit from the normal one). There are now few new greens coming up, looking much better. We have never done anything, but the next buy neighbour could have done someting 10 yrs ago (it is on their land too). The first part was ok, but not the spraying last weekend (we'll do nothing more until late fall). But we also have municipality people with their rules, taking no consider -the want the sight to be clear for cars. Right now only wish we had some (blue) foam here in Sweden to add to the result. [also saw an experiment using the JKW plant sap mixed in to fool the plant to get the rest down. Something from Wales]

I bought a stem injector from the UK last fall. Did a combination of injecting the largest stems of my big patch of knotweed and foliar spraying twice with a 2 week break in between. This killed about 90% of the knotweed and it's rewarding to see the area not being taken over by knotweed for the first time in years.

Suprised that they still sell Roundup.

Great video, except right at the end it was a little unclear. Under what circumstances should one do 2 injection applications -- one in middle of summer, one in fall?

Very nicely explained.excellent information. Genuine person with no monitory benefit

Bravo.......... knot weed.........I grow not grass............that's sound like nut and chocolate stuff......cheers

Thank you very much. I needed this!

I'm looking to clear knotweed from the side of a river. Is it safe to use glyphosate via your method with the foam near water?

My husband and I purchased a house last year in the winter and shortly after the snow melted discovered we had a knotweed infestation. We have a small stream that runs behind our house that the knotweed seems to be quite attached to. This year it has started encroaching further into our yard toward the driveway. In my frustration i chopped a bunch of the stalks down as close to the ground as possible and plan on burning it once it dries out. I wish i had seen this video before making the effort haha What do you recommend to keep it from coming further into the yard while it grows before a fall herbicide application? Im afraid if we do nothing it will keep coming closer to the house and become even more of a headache.

What about other foiliage or trees intertwined when spraying

Im going to buy your product and try it this fall! In the meantime what can be done? Ive been pulling it, putting it in thick contractor bags and garbage cans with lids until it dies clmpletely next season. Then Ive been throwing a bunch of roundup on it and covering it with thick tarps to smother. Recently bought a new house last year, and my neighbors yard is infested with it and they do nothing about it ! Ruined my attempts at a garden last year.

bro, thank you!! JKW is a beast.

In the winter, I started beaking off stems of really tall ones. Maybe 15 feet? I'm not allowed to use any chemicals there. There are some new ones growing from the same bases, but also some little new ones that I've started digging up. They are all growing up through our Forsythia, and I don't want them to do this again 😢.

Hi there - thanks very much for your video. I have a small infestation of around 4 stems in a very coveted part of London. I poisoned about 5 years ago and this is the first I’ve seen of it since its last treatment, the neighbours have built a wall and disturbed the ground which is why I think it has returned. When I treat this new growth, should I dig it up after the herbicide or should I leave the soil alone? I don’t want it to spread to the neighbour. Thanks!

I have tried adding compost on top of it and keeping it wet to drown the roots. So far no success stopping it. I'm going to try to burn it out by adding fertilizer now.

Knotweed sucks... but in my opinion, mugwort is worse. It stinks and isn't fun to break in half like the knotweed.

What if you cover with concrete?