Japanese Knotweed

[Equus]

strath44 said:

Interestingly I was at a old mansion in Argyll last summer and it had 4 varieties of knotweed in the garden "on display" which were brought to the uk several centuries ago!

That is interesting! Can you remember the name of the mansion?

I was under the impression that the belief is that every individual plant in the UK is derived from a single female example (hence pure-bred Japanese Knotweed cannot propogate sexually, though it can hybridize with Russian Vine to produce seed).

[993AL]

Beware!!!

[Equus]

993AL said:

Beware!!!

That's Castex's back garden as it is today, presumably?

castex said:

Dig deep. Be thorough.

[bernhund]

Condi said:

Wacky Racer said:

The best thing to treat a smallish area is Roundup TREE AND ROOT killer.

NOT just ordinary Roundup....This is very important.

Gone completely in 2/3 years.

Its the same stuff, the tree and root stuff is 480g/l, while regular roundup is 360g/l from memory. So slightly stronger, but with regular application it will have the same effect much cheaper.


OP: really not an issue everyone makes out it is, glysphosate will control it, even if it takes a year or 2 to fully eradicate.

+1. There was knotweed at the bottom of our garden when we bought the house. Every year I hit it with glyphosate and it went completely after 5 years. Just don't get the spray on anything else!

[Harry Flashman]

Without reading the rest of the thread, we bought a house with Knotweed. We have renovated it, and it is our dream home. Thread here, I think there is some Knotweed stuff in it somewhere.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Anyway, the sellers had started an insurance backed eradication programme with a certified company. It was two years in, and there was no visible sign of the weed, but a fenced off area in the garden indicated the treatment site. Our last treatment is this spring/summer, but the work has an insurance backed guarantee so they come back for free and continue to treat if it shows itself again in the next 10 years.

Accord Mortgages (who I have used before) were excellent on this: easy to reach, knowledgeable. Their requirement was that a treatment plan with guarantee was in place and being stuck to. I used a mortgage broker that I trust, but you may be able to speak to them directly.

No regrets.

Until the weed comes back like some sort of zombie triffid monster and eats my house, which it will if some of the doom mongers on this thread are to be believed

Treatment area is behind that orange netting at the left of the photo, so not exactly swamping the garden, to be fair. The brambles you can see on the other hand...Jesus. Getting those out was the opposite of fun.

78 back garden by baconrashers, on Flickr

Edited by Harry Flashman on Tuesday 13th February 13:08

[Temo_Wil]

Thanks for all the reply’s.

Will update on how the negotiations go...

[Johnniem]

I recently attended a seminar on this subject (CPD requirement for my profession, not by choice!). They confirmed (which I think has already been stated several times) that so long as the company doing the knotweed eradication is offering a full service guarantee, then mortgages can be sourced without any problem. Company expressed the view that untamed bamboo is actually harder to get rid of than Japanese Knotweed. I can attest to the bamboo thing. It is rampant in parts of my garden and grows at a furious rate. Cut it and it spreads horizontally under ground. Evil stuff!

[motco]

I believe that pampas grasses in the front garden can get you into trouble too...

[Steve_W]

Apologies for bringing an older thread back to the top, but this university study intrigued me:

http://www.bbc.co.uk/news/uk-wales-south-west-wale...

Basically, they reckon that, regardless of claims, knotweed cannot be eradicated!

[Mr Pointy]

I don't quite understand what the researcher is saying. If they only tested very low doses of glyphophate & it didn't get rid of it why didn't they test with a range of doses to see if more was better?

[ooo000ooo]

Planning permission has been applied for on a piece of land nearby that had Japanese knotweed a couple of years ago, the house nearest were told at the time that nobody would be allowed to build on it for 10 years afterwards and they stopped their own plans to build an extension because of this. I can't find anything that states this, anyone know any definitive rules on this?

[Timmy40]

Wacky Racer said:

The best thing to treat a smallish area is Roundup TREE AND ROOT killer.

NOT just ordinary Roundup....This is very important.

Gone completely in 2/3 years.

I use petrol to kill it. Works really well. Cut the shoots off near the ground, they're hollow, pour petrol into the hollow stem.

[Timmy40]

Steve_W said:

Apologies for bringing an older thread back to the top, but this university study intrigued me:

http://www.bbc.co.uk/news/uk-wales-south-west-wale...

Basically, they reckon that, regardless of claims, knotweed cannot be eradicated!

Nonsense. Complete nonsense. I've eradicated knotweed on several patches of ground.

[Equus]

ooo000ooo said:

... anyone know any definitive rules on this?

No, there are no definitive rules.

Contamination of a site (whether by invasive species or ground chemicals) is a valid and material Planning consideration, but can usually be dealt with by a suitable Planning Condition(s) requiring that details of a remediation strategy are agreed and implemented prior to commencement of works.

It certainly wouldn't be legal or appropriate, in Planning terms, to impose a blanket 'no development within 10 years' rule on a site, but the onus would be on the developer to show that either the risk has already been dealt with, or that a programme of appropriate further remediation/mitigation works can be put into place.

Similarly, there is nothing under Building Regulations that fundamentally prevents development of a site on which Japanese Knotweed has been identified.

[Lotobear]

I agree, it's bks.

We had a very large, huge in fact, and well established stand of Knotweed that crossed three boundaries (I mean the height you could lose yourself in). I got rid of it, took 3 years and occassional recurring shoots up to year five but I got rid of it though a process of cutting treating, and removing the rhizomes by digging them out, drying and burning them.

That was 10 years ago and its gone now.

So yes, utter ball cocks

[Equus]

Timmy40 said:

Nonsense. Complete nonsense.

Agreed.

It may be that the study is being misquoted/misrepresented, and what they are trying to say is that it will never be practicable to completely eradicate the species from a geographic area, but to say that a cluster of plants can't be eradicated from a single site is absolute tosh.

[Timmy40]

Equus said:

Timmy40 said:

Nonsense. Complete nonsense.

Agreed.

It may be that the study is being misquoted/misrepresented, and what they are trying to say is that it will never be practicable to completely eradicate the species from a geographic area, but to say that a cluster of plants can't be eradicated from a single site is absolute tosh.

Yeah I see what you mean. Bit of journalistic license going on. Lets face it if Braken was a new invasive species they'd say it was worse than knotweed. I treat braken and knotweed the same, both take 3-5 years to clear out. I suspect the reasearchers wouldn't have tried out my highly effective 'petrol' treatment either

[Lotobear]

...more likely that the research funding stream depends on their finding!

ahem, ...dear Roundup the field trials are not quite conclusive yet and we need to conduct a further 3 year trial and them we might be able to say that you're product is 100% efficacious in the treatment of Knowteed...can we have some more funding please, and can we run the trials in Japan?

[Timmy40]

Lotobear said:

...more likely that the research funding stream depends on their finding!

ahem, ...dear Roundup the field trials are not quite conclusive yet and we need to conduct a further 3 year trial and them we might be able to say that you're product is 100% efficacious in the treatment of Knowteed...can we have some more funding please, and can we run the trials in Japan?

I'm currently trying to see if I can successfully grow Wasabi and Ginseng on an entirely different note. Trying to persuade the wife I need to do some fieldwork in Japan. She seems unconvinced so far.

[Andehh]

Mr Pointy said:

I don't quite understand what the researcher is saying. If they only tested very low doses of glyphophate & it didn't get rid of it why didn't they test with a range of doses to see if more was better?

Yeah, this is what had me annoyed at this article & study. Turns out using very low dosages doesn't kill it. Well, excuse me for being a rocket scientist, so use high dosages!?

New study; it take me an unrealistically long time to drive a long distance, based on me doing a very low speed. Therefore, it's impossible for you all to drive long distances.


Something smells fishy...