looking to buy a house and the surveyor has just found japanese knotweed in the garden.

What do I need to know – or do I just walk away now?

walk away, your mortgage company probably will

Walk away pronto, i encounter this in my business, it is a total nightmare.

I’d by suprised if you’d get a mortgage on the property anyway, if you want to re sell you won’t be able to.

You can seemingly kill it with Tordon….but it hibernates for up to 25 yrs and then re appears 🙄

Clicky

What do I need to know – or do I just walk away now?

Major issue.. options:

1. Survey

2. Dig it up + watching brief from a specialist contractor to excavate a buffer round each grow area. EA suggest 7m radially from edge of visible growth and 3 below of soil – in reality you can do less… but still give youa large colume of contaminated soil – diposal cost and tax very high.

You can also kill it off using a range of chemicals such as glyphosate based herbicide – works best if injected into stems – this method can take 3 years or more to kill it off….

You can also use a herbicide containing picloram (active agent in tordon) but it is nasty and should not be use near water courses etc.. but it kills it much quicker but does sterilise the soil for sometime, though grasses will grow so no trees etc.

it is a right royal pain!

looks nice though and you can make crumble and pies from it though this is not a formal remediation technique!

http://news.bbc.co.uk/local/sussex/hi/people_and_places/newsid_8634000/8634285.stm

also if you spread it then it is an offensive under the Wildlife and Countryside Act 1981…. so don’t what some idiots do and strim it next to a river…

nuke from orbit
literally

You’ll need a boat…

As per rootes – it’s a PITA and is an offence to allow it to spread beyond your property. Excavation needs a big hole – I once visited a site in Weybridge where the excavation would have meant removing the client’s entire garden, plus some of their neighbours and the hotel car park to the rear…

If you are mad keen on the house get a quote for removal from a decent company (never had course to use these but had a few chats on the phone with them) and use that as a starting point in negotiation.

http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=218

Get a quote to dig it out and for full eco friendly disposal use a rocket in vessel composter – I believe Environmental charity Groundwork use it quite a bit.
pdf linky

I advise on this at work, and suggest you try a company called TCM if you are desperate to purchase. they’d be able to advise about the most efficient way of eradication – under some conditions they can guarantee within a year (direct injection into the stem), but this needs to be started at the start of the year. dig and dump can be massively expensive due to rhizomes extending out 7m in all directions.

I was under the impression, and I could be wrong here, that because it’s an ecological menace the council have to get rid of it for you?

EA

Landowners are not legally obliged to remove Japanese Knotweed, unless it is causing a nuisance to neighbouring property. However it is an offence to plant, or cause Japanese Knotweed to grow, in the wild.

Wow, never knew this was such an issue. My parents bought a house that had Japanese Knotweed in both gardens (rear garden was around 90ft) and my Mum (who likes gardening) got rid of it in three years, not sure what she used but I know picking every little bit out of the soil was painstaking!

You can strim it down with a blade, allow it to dry out then burn it. iirc form one of my courses average is about 3 years to get rid of it. I hate this stuff along with Giant Hogweed and Himalayan Balsam. Waterways around me are full of the stuff 🙁

[video]http://www.youtube.com/watch?v=FZUDxufmfN0[/video]

Plenty of advice on you tube

You can strim it down with a blade

Not adviseable as this will spread it.

Actually my earlier comments referred to Bindweed. Which you also shouldn’t strim due to spreading it around.

Hit Bindweed with Roundup (Glyphosate) in the Autumn before the leaves go yellow. Done right it won’t come back.

I work for the EA and we’ve done it at work. Should add a 2 meter wide strip was left right by the bank edge.

It can be killed in as little as two seasons using a herbicide, if you’re diligent, have the resources and have planned soundly.

Its possible to get two doses of herbicide in per growing season, with soil turning to stimulate fresh growth to allow the leaf area for the second dose.

Its a high maintenance technique though, but I’ve successfully used it to eradicate knotweed from 15,000 cubic meters of ‘as dug’ soil.

If it’s a smallish, well contained clump it can be got rid of fairly easily, you just have to do it right. We had a big old clump in the corner of our garden at our old place, growing under a wall and everything. I got rid of it in one year with no recurrence in the four years afterwards.

What you do is: wait until September (just after it has flowered, if I recall correctly) when it starts taking nutrients into its roots in preparation for winter. Then you hit it hard with the strongest glyphosate (Roundup) weedkiller you can get your hands on, every few days for two or three weeks. I used a couple of litres of the stuff in the end. Cover the leaves in it so the plant is dripping (Anything nearby is going to die, so shift anything you’re particularly attached to). The plant sucks down all the lovely juicy poison, and dies over winter. Then in spring you cut down the dead stalks and burn ’em – job done.

Do not: strim, flail or otherwise cut and spread the stuff, it can grow back from a fleck of stem less than a couple of mm long. This is how it spreads. All the Japanese Knotweed in the UK is a clone of a single plant, spread by people chopping it down and dumping it.

As above, that’s exactly how we got rid of our small clump of about 6-8 stalks about 6 foot high. Whacked it with glysophate in autumn 2 years in a row, nowt showing after 6 more years.

Anything nearby is going to die, so shift anything you’re particularly attached to

I’d see anything nearby as colateral damage, if it’s close enough to get hit with the Glyphosate it’s close enough to potentially have knotweed rhizomes in it.

I’d see anything nearby as colateral damage, if it’s close enough to get hit with the Glyphosate it’s close enough to potentially have knotweed rhizomes in it.

Good point. You are quite right: nuke the site from orbit. It’s the only way to be sure. 😉

I should add that our clump was a good sized 40-50 stalks and had been lovingly cherished for years by the previous owners, who didn’t know what it was but thought “it was doing so well it was a shame to get rid of it”. 😯

kin hell this is day of the triffids stuff!

We’ve got a load growing behind our back fence. The land is owned by Railtrack. As it keeps sprouting up in our garden can I get them to do something about it?

Coyote – phone the network manager or environmental manager for the area where you are, and ask for urgent treatment. they will do something, probably spraying. keep on at them. they will have to enter it into their marlin database, which should ensure continuous treatment…

Cheers Fatmax, will do!

There are strict laws on the disposal of it and even the soil in which it grows. I don’t know what they are but I know they exist and they are indeed strict. I wouldn’t even go in the garden or it’ll start growing up through your feet, no joke.

cheers all for the replies.

coyote- from hunting around the web it looks like you can sue if its encroaching on your property from someone else’s

TCM

Thurlow Countryside Management
Excellent Company – experience of them on a few larger jobs in London area (olympics relocations etc)

http://www.t-c-m.co.uk/

Also have used Landtech for eradication:
http://www.landtechuk.com/ both for seasonal glyphosate stem injection and spraying (where time allows 3 years plus) but also for picloram application.

Both cause also provide watching brief for dig and dump so you only excavate the minimum soils buffer around stands – saves weight and this costs.

Also you you do a dig and dump – many skip contractors will either not take it or charge you lots more than normal. Whilst many landfills are permitted to take knotweed contaminated soils they often restrict A. because soils takes up void space or B. they are filling close to the edge of a cell and knotweed if it starts to grow can damage the cell engineering.

Same it is so invasive as it actually looks quote nice.

Same it is so invasive as it actually looks quote nice.

should of been:

“Shame it is so invasive as it actually looks quite nice”

Yes, it’s very difficult to find good companies to sort out this kind of problem. I had an overgrowth of stuff looking very similar to that shown here. I called 3 companies who claimed to specialise in this kind of thing to take a look at it. Every one of the cowboys insisted that the weren’t weeds. I sent them on their way.

Out of curiosity, would caustic soda treatment not be efficient? When I “treated” my grandad’s garden paths with some they were vegetation free for years.

should of been:

Should have been.