To ask how you deal with Japanese knotweed

[rogertherabbit]

Hi all, I post a couple of weeks ago about a house I've fallen in love with but it was quite near a main road. This turns out not to be an issue, but I've now discovered there is knotweed in the garden! It's not near the house and is being treated, but I'm looking for your experiences of dealing with this stuff - there is apparently a 10 year plan in place, but I don't really know how much of an issue it'll be. Plus I don't know if the bank will give me a mortgage 😟 Hoping with the treatment plan they will, but I just don't know!

[ShatnersBassoon]

Glyphosate works on it. You might need to persevere for several years to make sure you've killed every last shoot, and worked out where it's coming from and made sure that area is treated too, but you can get rid of it.

I don't really understand the hysteria about knotweed. It's a pain in the arse, but not anything to lose sleep over.

[Parietal]

we bought a house with knotweed (only 2 plants, no mortgage). I treated it myself with glycophosphate and it is gone after 3 years. There is lots in the area which the council have been treating, so seeds may come back, but as long as you recognise it & treat it as soon as you see it, then it shouldn't cause a problem. The problem only comes if people leave it untreated.

[MaisyPops]

PeaFaceMcgee
I'd always been told that if there's a weakness or crack then it exploits it and opens up bigger cracks.
I'd been told that it can affect seemingly ok houses and not just ones that are really run down.
If not, then I'll take it back

[rogertherabbit]

Hippee no it doesn't begin with H, but you're right - seems to be associated with church yards! Maybe I should pop in to the church yard and see if I can find the knotweed....
Sounds as though it's actually quite a common problem. The documents through from the eradication company seem quite thorough. They provide a 10 year guarantee which I supposed is good

[Frillyhorseyknickers]

And to do so it would need to be really bushing throughout the bottom of the house.

Please explain what you mean?

The property foundations are not usually visible for inspection prior to a purchase, you don't know what hairline or fissure cracks may be present - if the rhizomes start to work at a small crack, it will destabilise the foundations of a property.

To the park ranger earlier up the thread - managing and irradiating knotweed in a large area is completely different to purchasing a property next to an infestation.

[Zafodbeeblbrox10]

Glysophate.. mmm.. Nice stuff that too!

[caroldecker]

Frilly here is the RICS advice. There are some claims that Japanese Knotweed can result in damage that is more dramatic to buildings. These extreme problems are thankfully very rare and exceptional.
Basically only the Uk appears to be that bothered about it.
BTW it is not illegal to have on your land/garden - only if it causing a nuisance to others.

[NonStopDisco]

I'd be a little uncertain, just because glyphosate is always disputed and therefore could be at risk of being banned (EU have decided it is safe so far, but that may not be relevant, plus other countries have banned it anyway). However there are alternative broadleaf herbicides that would treat knotweed.
Do you have details of the treatment plan?

[NonStopDisco]

Oh sorry, just seen that you do, and there's 10year guarantee- assuming it's a well established company otherwise that could be meaningless!

[SilverLegoBrick]

The knotweed around here in France has been around for years, it's not a new phenomenon. It gets cut back by the council and then it regrows. People I've spoken to about it genuinely have never heard of it. It's mostly along roadsides and waste areas awaiting redevelopment but I've also seen it along roads where there are houses. DH and I were horrified at first but quickly realised that it's a total non-issue. Weird how it's so different here! No idea about other countries...I believe they eat the shoots in Japan?

[Celib]

Re Frilly's posts. The advice not to buy any property with Jap knotweed beg the question as to how the owners of 10% of the housing stock in the UK which is affected by knotweed will do. I suspect that if people cannot sell if they declare it, they will not disclose it on the TA6 form.

Many people are already hiding it and not disclosing it. It is prolific in parts of London and in all the cases I know of, builders are being employed to conceal it so the owners can sell.

People have many reasons for needing to sell: relocation, larger family or downsizing, unable to pay the mortgage. If all their houses are repossessed and they are made homeless, I suspect people will just not declare it.

[LightsInOtherPeoplesHouses]

no doubt because it probably seeded for a few years

No, it's because the roots aren't dead and if disturbed it can start growing again. Glyphosate can kill Knotweed, but it can take years and repeated applications - and even then it might not be dead dead and if the roots are disturbed could start growing again.

And no seeds - "Only the female plant has been recorded to date in the UK, therefore even where Japanese knotweed seeds are produced, they have not been fertilised by the same species, and are sterile and unable to produce new plants."