Japanese Knotweed - would you buy a house with this problem?(93 Posts)
Have seen a lovely house within in our budget in perfect location near good school, quiet road, great size. But one major problem: Japanese Knotweed! The vendor is aware and is putting a legally binding (for them) treatment plan in place. I am aware that this issue could have an impact on home insurance and getting a mortgage. Are we crazy to even consider the place? So far we have not put forward an offer, just researching the issue. Has anyone got any experience with this?
Run. Run faster. Faster than that. Run. Run. Run. Don't look back. Just run.
No, not in a million gazillion trillion years.
NO NO NO NO NO NO NO NO NO NO NO NO NO NO NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Even with a treatment plan in place I would be very wary. I've only heard bad stuff about it.
Nooooooooooo!! Run and check none of it is on your shoes!!
It can spread via seeds on shoes apparently
Our jkw problem was bad but it can be sorted out. It takes time, you won't be able to plant anything for years, and you will need to get it treated many times a year. You could keep doing that, or dig it out. All this costs obviously, and there are rules about getting rid of soil.
Sort of luckily for us we moved in, cut it down and burnt it, treated it for a year THEN our garden had to be dug up by the council for a completely unrelated reason, so it wasdealt with at this time.
Good luck, it will take time and money, but if it's the only way you can get a house in the area you want to be in, then why not.
Sorry , should have also said we got our flat in a sort after area because no one else was prepared to take on the jkw. Ours was visible from space! Through cement, pavement etc etc. Two years after moving in and a specialist has just been to look at it and said it's not too bad. Is the house in London? If so and there is London clay beneath your garden things are reasonably positive as apparently it doesn't like clay and therefore won't go deep.
I can't tell you until you tell me what it is
Is it not just a plant? Why can't you dig it out and put it in your brown bin?
Yes, it's in SE London. At the moment it has actually not been priced down because of the knotweed. It came back on the market after an initial sale fell through when this issue came up in the survey.
No freaking way. Run. Take your family.
Japanese knotweed is an officially Invasive Plant. It is a zillion times worse than bindweed, brambles or anything normal. Tiny bits of it can sprout up into huge choking forests. It's illegal to put it in any domestic or unsorted waste. There is some growing near us in an electricity compound that the council have been battling with for years.
Ah well, I suppose I'd work our how much it would cost to get rid if it, then how long it would take to get rid of it ( you will still be able to use your garden in the meantime, but it won't be pretty ) put a price on this and offer that reduction.
We were only able to think positively about ours as DH has qualifications in plants and stuff( I pay attention me) so knew what to do.
In London I'd be worried about it spreading into neighbouring properties and then coming back under the fence for ever. Not in West Norwood by any chance is it?
On phone so can't do links, but there is a lot of useful and interesting info on JK on the Environment Agency website.
Thanks bike. Will check this out.
Fossil, it's not in West Norwood, but not too far away.
we did! Though it is not seriously entrenched. Tis our forever house though, so we can afford to wait it out and blitz it until it gives in - if we'd wanted to sell within a few years it might be a different matter. It is also a big garden so not using the bit of it with the knotweed in is not hugely problematic for us. There is a lot of hysteria about the plant. Sure it is invasive, and you have to know what you are doing, but I spoke to a number of experts and none of them said it would put them off buying a house. You basically glyphosphate it to within an inch of its life, takes about 5 years but it apparently eventually gives up! Mortgage companies might be a different issue - luckily for us jk didn't come up in the survey, it was only my MIL that noticed it.
We had a flat with this in the garden once. One of my main criteria for house buying now is that any potential house must not have knotweed around it. I'd find somewhere else to buy TBH
I'd be suspicious about that DM article btw. More likely if it was a new build is that the knotweed was in the ground under the house already when it was built. That would indeed be a nightmare, and why jk is so feared by developers. For more established houses, everything we were told is that it it a highly invasive and difficult weed, but not a daily mail-style horror triffid!
OMG Vez! Where is it? Can you pm me? Seriously worried ...
God no. Just don't do it
I only say because we rented a house that I think had it at the end of the garden, was much younger and less clued up then. It can hang around where there are derelict sites or on old bomb sites.
Bibbity don't panic, you would know if you had it, very distinctive stemmy shrub with leaves a bit like lilac on red speckled stems. Grows to above person height and spreads quickly.
Ves, I'm wondering if this could be the house in SE London on which my son had an offer accepted, but when the surveyor noted the JKW, the mortgage company withdrew the offer. He tried to find an alternative but was emphatically told that no one would consider it. Frustrating and expensive.
Someone was on Radio 2 talking to Jeremy Vine about JKW recently. They had the most horrendous time. Apparently you cant ever totally get rid of it! They had someone on who deals with it and they didnt have a good word to say about it!!
House will be uninsurable so walk away unless you are mad.
It wouldn't phase me. But I'm a qualified horticulturist and I know how to deal with it. You just have to keep applying glyphosate religiously; eventually it gives up.
No I wouldn't. I feel really sorry for homeowners who discover this problem on their property, not least because they will find it almost impossible to sell. The vendors will be rejoicing for the rest of their lives if you buy their house. You, on the other hand, will not. Why make life difficult for yourself?
You are no doubt right, Rhubarb, about it being possible to get rid of it from your own garden. The problem my son had was that though there was none in the property he wanted to buy, the surveyor looked over all the boundary fences and spotted it on adjoining land. Apparently they are all now under instructions to do this, and it resulted in the mortgage being refused.
I felt sorry not only for the vendor being stuck with a virtually unsaleable house, but for the blissful ignorance of the neighbours, liable to be shattered when they too try to sell.
herhonesty, that isn't true. Our house is perfectly insurable. I think it's telling that the qualified horticulturalists on this thread are the ones saying that it wouldn't phase them!
But if you have it on an adjoining property you could install a root barrier around your boundary to stop the spread of it into your garden. It wouldn't make a property unsellable.
I agree with Rhubarb, it is treatable with Glysophate but as far as I know sucessful treatment can take up to three years and you will have to take precautions with moving any contaminated soil as it is officially a controlled waste.
Libelulle, as you say, yours did not come up in the survey, and presumably your insurers know nothing about it either. The issue is not whether it is a serious but treatable problem, but that regardless of the possibility of eventually eradicating it, mortgage lenders simply won't lend.
that's true hintofbream that many mortgage cos are running scared, and that will be true issue for OP if she decides to go ahead - but insurance is a different question, and unless the kn has grown unchecked for decades, the house itself is not at risk if it is not a new build. I am not trying to claim kn is not a big issue, I just think there is quite a lot of ill-informed scaremongering on this thread that is not helpful. OP if I were you, I'd get specific advice from knowledgeable experts about this particular house - without knowing the extent of the infestation, there is no way of knowing how much of a problem it is likely to be, even for the mortgage company.
A friend's husband worked on a building site of a large hospital and JKW was discovered. All of the soil was dug out to a depth of 6 feet and treated as hazardous waste. I'm interested to know if this is just a JKW hysteria, given Rhubarb's comments, or whether it really is that nasty?
Worldgonecrazy - that is one of the treatment options available and generally what happens on a large scale construction site. They take this approach for several reason 1. in order to avoid spreading with machinery while building. 2. It is quicker than treating it with glysophate over several years.
Another alternative taken by construction companies is to bury it deep underground and cover with with a protective membrane. If you remove the soil from site then yes it is a hazardous waste. But if you aren't planning on re-landscaping your entire garden there is no need to take this approach.
Libelulle, your advice to get advice from experts familiar with the property is very sensible. Also worth asking agents if there have been any offers which have been withdrawn, and if so was it because of the JKW and mortgage problems?
NO! It grows 10cm a day! Run like bloody hell. I think you even need council permission to burn the flippin' thing.
Just found this from a quick google. If the sellers have a treatment plan in place have they already had experts in, can you aske to see their findings?
www.jksl.com/private-gardens-and-mortgages.htm sorry can't do links properly
It can be dealt with but I'd avoid it like the plague. After all, when you come to sell the place anyone doing a search will find out that you have had a problem with it and that will put people off, regardless of whether you've fixed it or not.
Or you could offer them 30% (or more) under the asking price. In this market they'll be glad of any buyer.
Blacktea is correct - it's quicker and easier for construction companies to take that approach. They already have the heavy equipment on site anyway.
But Hintofbream has a good point about adjoining land. I wouldn't buy a house with a garden backing onto a railway line that was infested, for example, because you would be acting like King Canute against the tide.
A lot depends on how bad the infestation is.
I think it depends on how bad it is and how much you can get off the price. And whether you couldn't afford to live in that great location otherwise.
My parents had a small outbreak of JKW in their garden. My mum got rid of it, basically by painstakingly painting each leaf of each plant with concentrated Roundup for many many weeks, and also directing each tendril to grow into a jar of Roundup. However, this is seriously toxic so not a suitable approach if you have small DCs.
Peetle searches will only find out you've had it if it's registered with the council or some other authority.
Well I work in bleeding insurance and some insurers will not insure you if you have jkn. If it's come up in a survey, it's a problem. I would advise against buying a house where you may have insure via a limited pool of insurers.
You can eat it. <helpful emoticon>
I remember an episode of 'homes under the hammer'. There was a house with jkw that was completely un-mortgageable. It had grown into the foundations and part of the house had to be demolished.
They were very negative about it and the buyer was told that he would probably not be able to sell it on as it would have to be cash buyers only and was also uninsurable.
Sorry. It also seriously undervalues the property so you need it reflected in the valuation. You could call your local council for advice as they have to monitor it on a regular basis.
I'm an ecologist and part of my job is producing jk treatment plans. it wouldn't put me off buying my dream house.
If I were you I would have a proper Japanese knotweed survey and management plan done, the vendor may have done this already. Do you know how big the patch is, whereabouts in the garden it is and whether it is also present on adjacent land?
Treatment will probably be at least 3 years of herbicide spraying twice a year.
The wildlife and countryside makes it illegal to plant Japanese knotweed or allow it to spread on to adjacent land so if it is coming in from next door the neighbour has a legal obligation to treat it.
It is not harmful or toxic and is treated as contaminated waste because of it's legal status and because the roots and pieces of live stem can sprout and regrow from small pieces. It does not spread from seeds.
Defonitely find out what you're dealing with and the treatment implications before writing it off. JK is everywhere in this country. If it wasn't treatable nothing would ever get built!
Sorry, Wildlife and Countryside Act
We have exactly this issue at the moment. My solicitor told us to avoid. Who knows what environment obligations may apply in the future. He also said that we should be seeking a significant reduction in price if we did go ahead.
It can lie dormant for years and then come back with avengance.
We are going to get a specialist in to have a look as it has apparently been eradicated but I am not sure whether the fact you have had it blights the property forever.
Pushmepullyou I'm also an ecologist! snap. Good advice given there.
Black tea / pushme, sorry to hijack but can either of you recommend a specialist. There seem to be loads on google!
I presume the problem is worse if it is on a boundary (as is my case) as you can't treat your neighbours property and it just reinvades?
Does anyone have an opinion on the impact on property valuation for a patch about 15m from house, but crossing the boundary?
sevenbubbles, in my son's case, as I mentioned above, the JKW was not even within the boundary, which itself was about 20 metres from the house, but on adjoining property, and that was enough for the mortgage to be refused.
Thanks hintofbream. We have been told by HSBC that provided it has been eradicated it is mortgageable. But they are going to want to see the treatment plan yet.....
Sevenbubbles I linked to one earlier that I found from randomly googling. I don't know if I am allowed to give recommendations. I will send you a PM
Thank you black tea!
Think I have answered my own question on value - https://consultations.rics.org/gf2.ti/f/275138/6179845.1/pdf/-/Japanese%20Knotweed%20and%20residential%20property.pdf
It's only consultation but looks likely to be the way things go I suspect......
Sorry on iPhone and can't work out how to do links.
We had some in our garden a while back. I assume it couldn't have been that bad a case because DP went out every day and dug it out whenever he saw any growing and eventually got rid of it all. That was about eight years ago and it hasn't come back. Fingers crossed...
We also had some in our garden, dh treated every year with roundup and it's gone now.(4 years)
We'll keep checking and if any more appears we'll treat it. It's not close to house. Not been a big problem for us because there wasn't much to start with and we kept on top of it
glad to see a few more professionals on the thread giving useful and non-alarmist advice. That RICS document was also very helpful and balanced about the usual extent of and damage caused by knotweed in a domestic situation. Hopefully in time mortgage and insurance companies will start to be a bit more reasonable about it all - sounds like HSBC already is. After all, I read somewhere that in the south of England there is knotweed in pretty much every square kilometre of urban environment. Which means it is 'near' many hundreds of thousands of properties!
cant believe the hype. jkw as you seem to have fondly termed it is a plant, pure and simple, it is of course a rather robust and persistant little bugger but it does not as far as i am aware have super powers and unlike some of my previous acquaintances will not spend years trying to enter my house uninvited. If cast out and left to defend for itself in the wild it will of course attempt to to establish deep roots in any uncontrolled area where it remains unchallenged. However a determined and persistant desire to rid this minor irritation will almost certainly see a total and completely satisfying demise in its attempts to encroach on your personal and private areas. No building foundations have been fundamentally undermined by this plant where it has occurred after construction. However it is imperative that no new development should be allowed to occur on any land that this weed has corrupted in recent history. Please take note that there are many other invasive weeds that your insurers and mortgage lenders are not yet aware of but may pose a future threat to your security and feeling of wellbeing. Creeping willy and ivy nuff but to name but two. So watch your backs ladies you never know whats creeping up on ya.
I am watching this thread with interest. Our neighbour whose garden backs onto ours has allowed a huge jkw patch to spring up right along his back fence - fortunately we are separated by a paved access path, so we have a few feet between the canes and our property. We've spoken to him and he's doing something about it (and in the meantime we've found out another neighbour has written to the Council, so he's extra-motivated now), but I hadn't realised it would make our house unsaleable. Eeek.
As if we didn't already have enough problems with brambles & bindweed lurking in the access path!
You should not touch the JKW until the end of august/september or you just sisk spreeding it. It can be got rid off with a bit of patience and knowledge.
Copy and paste from another site on how to deal with it.
irst things first - wait until the end of August up north, early September down south. You need cheap glysophate - may be try an agricultural supplier - a mixing container and a syringe (no needle). You can get the latter at the chemist for about 30p although it can take a bit of explaining. A bit of food dye is useful too and protect yuorselves with gloves.
The mix is glysophate at 5 times the normal concentration (whatever is on the container) with water an a bit of food dye in a container you never want to use again.
Cut the stems above the first node (leaving some stem above to contain the herbicide). Inject 5ml of the mix into the end of each stem, the food dye makes it easier to see which stems you have treated. The syringe is marked, so it is easy to pull up a measured quantity from the container and inject the right amount. The plant draws the herbicide down into the roots as it prepares for winter.
The stems have to be left on the ground (on plastic sheet) to dry out. Burn them later (we go for Bonfire weekend as that caused least objection).
The next spring you will get a small amount of distorted growth, which you can treat with normal strength glysophate - we painted it on because it was in an area where food grew. You do need to wiat until teh growth turn green though - not much use treating it until there is chlorophyll to distrupt.
There will also be a small number of strong shoots, particularly from areas that are between nodes that have died off; the herbicide has just not travelled far enough to kill the root between the two nodes. Leave them to grow strong and then tackle them in the early autumn by injection.
The next year we had very very little growth and most of the nodes had rotted loose and we burned them.
There is one small bit to tackle away from the main area. The pillock there kept pulling up the shoots and consequently there has never been enough growth to effectively treat! So two years after the main area was turned over to cultivation, we are still trying to deal with that little area.
Just a note on the problems of digging it up; the original small problem area became much more widespread the year after the fence was replaced, all along the fenceline. We suspect that the contractors transported tiny bits of the broken root on tools as they moved along the fence line replacing uprights.
And when we had out first bonfire, we added one or two nodes that had broken away during the injection process. The following spring one which was very very charred and partly carbonised started to sprout!
So it is tough.
The major problem we found was that we had very wet Septembers when the regrowth was doing well and we did not have two consecutive dry days to treat the plants. Had those months been dry, I think we would have cleared it completely by the third year.
my first thought in response to op's question was "no thanks!" but if it is an isolated patch within the property might be tempted for the right property and a large discount! patches outside my direct control would be less appealling as i couldnt guarantee that they would be eradicated so i could be left with problems.
i dont remember seeing anyone else explaining that jkw comes from the upper slopes of volcanoes in japan. this explains why fire doesnt bother the stuff and it has no known predator in this country - yet. i believe that there are trials at the moment on some sort of genetically modified creation which will be released to control it..... horrible thought and based on past disasters the cure could be worse than the disease but we will see.
as said above the plant has to be tackled seasonally and with a management plan. options are injection (but the hollow stems are divided/sectional so not suitable for large patches), painting/spraying, excavation for licensed disposal offsite or excavation for encapsulation on site (normally buried). the latter 2 are the only option for developers wanting to get on with construction as the first 2 take 2-3 years of meticulous work. attack from another site can be limited by installing a root barrier but this is impractical for most domestic settings.
the plant which is in the uk is only one sex (cant remember - maybe female?) so cannot be propogated by airborne pollen. if the other half turns up we are all in big trouble as this pest has managed to be widespread as it will sprout from the tiniest of rhyzomes (fragment of root) or by growing sidwways underground.
many make the mistake of overspraying thinking they will blast it but this burns the foliage back without affecting the troublesome roots. so follow the instructions and stick to dilutions and timings suggested!
the plant can bust up concrete and break into buildings despite what someone else posted. i have seen photos of it growing up the cavity of an external wall and poking out the parapet so it is a bu**er but possible to get rid of if tackled correctly!
calling the jkw experts please!
We undertook a determined assault on our knotweed last year and this year it is a seriously ailing plant (muahahaha). Instead of strong single shoots, there are multiple tiny little weedy bunches of distorted shoots (a couple of cm high). Thing is, they haven't grown at all since appearing in about April/May, in fact some of them look pretty withered and dead. I don't doubt the buggers have life left in them yet though.
So: wan we expect growth spurt later in the year, at which point we pounce with the glyphosate, or are they just gathering strength for next year?! Do we really just sit tight until there are leaves, or is there anything we can do in the meantime?!
Of course, we've barred all the doors and windows just in case it makes an assault on the house .
Leave them alone and wait until the autumn and then treat again with the glyphosate.
Thanks cantspel. It's counterintuitive to leave it to grow but I completely see the logic; I fear we probably did overdose on the roundup last year. Luckily we are not selling our house any decade soon!
libel your description sounds like the chemical burning of foliage i mentioned earlier. Don't over-do it on the attack! it just takes longer to get rid of it if you have sprayed too much or too strong. Good luck!
The flowchart on page 12 is pretty good for explaining what treatment plan options are:
Remember you are not allowed to throw it in normal skips/bins. The plant needs to be taken to specialist tips and for us its 30-40 miles away. We run a groundworks company and people have to realise if they want the plant removed for clearance and sprayed then you have to pay extra to take it to a specialist tip. We have a problem here on our land as its travelling down through the water course.
Yes tricot I fear it might have been Though compared to last year it does look much diminished all the same, so maybe we got away with it. It isn't a very well established patch, just the odd stem here and there, which might help? <hopeful> Still, we know now what to do! Quite like the idea of lulling the thing into a false sense of security before launching our attack
ve123 - I have lived in 2 properties which had it - one backing on to the railway line which goes through Herne Hill - the track was lined with the stuff, one in a back garden in Brixton.
It didn't spread into my yard from the railway line, thank goodness. It did come under the fence from a Lambeth owned property, and I got nowhere with Lambeth trying to get it dealt with. But I didn't know the all facts at the time, and just kept spraying glyphosphate on my side of the fence, and leaning over the fence and spraying theirs, too. It didn't spread. And, in all innocence, I sold the house without trouble.
Is the infestation coming from another property? Could the vendors take out one of those indemnity policies in case it becomes a problem after the treatment? Could you ask that the treatment guarantee be transferrred to you?
Apologies for the hijack, but how can I know for sure that what we have in our garden (rented property) is jkw?
It doesn't grow 10cm a day I don't think and I dont remember ever seeing those white flowers on the pics. Also it doesn't grow that tall - maybe thigh high. Otherwise it does look like the pics and it has the longest most intricate roots I've ever seen. It covers the whole extension of our garden, not just a patch and I absolutely hate it! It's impossible to have a lawn or plant anything else. But being a rented house we sure won't invest any time or money in getting rid of if....
Does the landlord have any obligations? We often trim it so that the dcs can still play in the garden and pull out or attempt to some of the roots and put them in our green bin, which maybe we shouldn't but what else can we do?
Thanks and apologies again for the hijack and long post!
If the canes are hollow with purple speckles then it is JKW.
By trimming it and pulling it up you are just spreading the roots. Dont put it in your compost or green bin as again you will spread it and it is a crimminal offence to knowingly spead it.
You cant force the landlord to deal with it so if you want to remain there long term and use the garden then you are going to have to treat it yourself. It is not expensive to treat but it does take time. You would need to leave it to grow during the summer and treat in at the end of august/september and if you have alot it will probably take at least 2 years before you will begin to see the end of it.
just by way of info, ours definitely doesn't grow 10cm a day and is definitely knotweed, so I suspect that growth rate is in ideal conditions!
I also have a flat with a garden backing onto the Herne Hill train line, which is completely infested with the stuff. I have to say though, it hasn't really spread into our garden - not sure if we've just been lucky? It didn't affect our mortgage or come up in the survey either (bought it about 4 years ago).
Thanks cantspel. Not sure what to do.... its very annoying that we can't use the garden and the only option is to treat it properly - a lot of effort even if not money for a house that we don't own and may not be in long term...
Also, if we treat it chemically will the Apple trees in the garden be affected? Ie, can we still eat them?
Run. Run like the wind. No amount of discount off the house will make any difference. It's very expensive and very very time consuming to sort. It can come up through the foundations of your house.
Wilding - [[ http://mayallroad.co.uk/?p=234 LOOK HERE!]].
I lived in a rented house with JK. It is actually pretty easy to kill, although it is time consuming. What you need to do is get some very strong glyphosate - I bought 'brush killer' strength, and used it neat, a strong stick and a sharp pair of secateurs. Cut each stem about 15cm above the ground, poke the stick down it a few times to break the cross pieces in the stem , then pour about 20mls of neat glyphosate down the stem. Works a treat. It takes ages to treat each stem though!!
We completed on a house in December after 4 months of fighting because the surveyor spotted knotweed. It is a house which will be our forever home which needed total refurbishment and was probably the only house this size in London we could afford so we fought with our lenders (HSBC) and our insurers and we eventually bought it.
The insurers were th biggest problem as there was evidence of subsidence which had been repaired and wasn't knotweed related but we got the current insurers to take us on.
I guess the knotweed came from fly tipping as our garden isn't fenced on one side. It has been a pain. The specialists said it was dying after the first treatment but it has appeared elsewhere since then and been treated again. It is definitely responding to he treatment but we have been told to keep our daughter and pets away from it to stop spreading and we can't plant anything or clear our garden. Thankfully we are unlikely to be able to afford to do the garden for a while but it does limit us a bit.
Would I buy the house again? In an instant. It is only a plant, after all and in the end we have a lovely forever house.
By the way I hate the hype about it. It has been around for years but has only just been noticed by lenders after DM type scaremongering :-/
Ps I agree with Zomax that there is too much scaremongering based on very little experience or practical knowledge.
I think if I could get a discount, a mortgage and insurance then I would still buy it(I'm not a horticulturalist). If this is your dream home and you're going to stay there forever then resale won't be a problem.
Your garden will be unusable for years, (well no landscaping or digging of any sort) but there are obviously treatments that work they just require a very diligent approach.
So don't dismiss the house but do a bit more research about the size of the problem.
Oh yes, well spotted. I wonder if they did buy the house.
Knotweedadvisor seems to have had a motive to reserect!
pm see if they bought?
I know it's an old thread, but it brought back a load of bad memories, and if anyone else were to ask I'd advise them tho run away as fast as humanely possible, and even so the knotweed would probably grow faster!
I was plagued by the stuff in rented accomodation a few years ago in Birmingham, and it was like a constant battle - not helped by the fact that I didn't know what it was at first and made it worse by trying to pull the stuff up!
And as soon as I thought I was getting somewhere, it would keep invading from next door (a rarely used back yard to a shop).
I felt like a superhero trying to defeat an all powerful baddie!
I DID however find out during my research into how best to thwart the stuff that it's EDIBLE - and found a recipe for a spiced apple and knotweed pie, which I lovingly baked and took great delight in eating! (It's actually quite nice, like a tangier version of rhubarb...)
Join the discussion
Please login first.