Knotweed - more than 7m and with treatment plan

[NervousBuyer2021]

So. Having walked away from one house after a bad survey (and seller not willing to work with us to deal with any of the issues) we’ve found what is the perfect house for us, in the perfect location for us...with a small patch of knotweed at the back of the garden.

It’s more than 7m from the house, there is also a small bit in a neighbour’s garden and the seller has already started treatment with herbicide through an approved contractor.

We’ve spoken to the contractor doing the treatment and he’s been very reassuring. He has looked in all neighbouring properties and only found it in two, both being treated and they’ll continue to survey neighbouring gardens and ours for 5 years.

We want to go back and ask him if a quicker (and maybe more effective?) treatment is possible, some kind of excavation. That would give us full use of the garden much quicker as otherwise the treatment takes up to 5 years. We’ll still have plenty of garden but will have to fence off the knotweed bit to make sure it’s not disturbed and able to spread as a result while the herbicide treatment is ongoing.

Wondering if anyone has been through the herbicide treatment programme and had success?

Also wondering if we are naive to think that this all sounds reasonable...we know it’s not ideal but it seems to be possible to sort?

I would.pull put of sale. It is notoriously hard to get rid of and can grow up through concrete.

Knot wood is perfectly treatable, calling it a "monster" is slightly hysterical. Horticultural experts are quite clear that ivy is absolutely lethal to bricks and mortar, yet people routinely grow it up walls.

We had it when we bought our house, and got a company in to deal with it. It was in two patches, one small, and one medium. It gets treated twice a year, with chemicals, and has nearly gone. This year it's not come back, so assuming it gets signed off by the company, then we can dig it out, and dispose of it. It hasn't spread after treatment started, and really hasn't been a major problem. Only issue has been not being able to work on that flower bed.

The area isn't fenced off, and it hasn't been a problem. We have dogs, but they don't dig, so it's not been any issues

My view, if you love the house, and you can get an insurance backed treatment plan in place, then go for it. We paid just under £3k for the treatment plan, which in hindsight, was a lot, but it gives us peace of mind, and the company guarantee to come back and treat it, if it comes back.

I’d actually not be put pff my this as long as I was sure that it was properly treated and the neighbours were too. But it doesn’t seem it is being properly treated.

However asking them to excavate their whole garden is insane. No ones going to do that.

We bought a house with jk in the garden. We dug up the root systems as far as possible and burned them, then treated what came up after that ourselves with roundup yearly. No fencing! By the third year it was gone and we haven't seen sight or sound of it since. That was 12 years ago. I get that it's a nightmare if you build your foundations on it, or leave it to invade your ruined castle, but I'm a bit mystified at the levels of hysteria beyond that I must admit. Maybe we were lucky, but it really wasn't a huge deal - the bloody bamboo was much more troublesome!

Thank you for those stories - those that have treated it, do you know if you need to declare it when you come to sell your house, as a historical issue even if not present at the time? Part of the problem is the extent to which it would put some people off, even if it is managed well, dealt with effectively etc.

I'm amazed at the hysterical responses to JK on here too....my partner is a landscape gardener and has treated JK and got rid of it before....he says ivy is far more damaging to houses....it's a plant not a toddler eating monster.

I don't know if you need to officially, but I don't think in practice that we'd be likely to declare that a plant that we hadn't seen in over a decade used to grow in our garden! Moot point though as we have no plans to move ever.

Maybe we were lucky, but it really wasn't a huge deal - the bloody bamboo was much more troublesome!

^ This
I’ve finally got rid of the bamboo that was in my garden, but all our neighbours have bamboo that keeps popping up under my fences.

My worry wouldn't in treating it/getting rid as long as the issue was reflected in the price of the house.

My concern would be resale - you've see how fearful people are when it's mentioned. Most people would run. How long do you plan to live in this house?

I live in an area where several houses have knotweed, especially those near a little brook, so I assume it is in some way related to the watercourse. I have not lived in a house with knotweed itself, but I do know people who have bought and sold houses that do.

We all know knotweed is a huge problem, but what I know about it is that it is manageable. So from my point of view I would want to know that it was being managed, and see details of the treatment plan. It is an offence to let it spread from one property to the next, so I would want to limit that possibility; proximity to a boundary would concern me.

That said, we know that it is a plant that responds to herbicides, that can be got rid of, and that actually there are several plants more concerning not currently covered by legislation. I personally hate wisteria on buildings because it can cause significant damage, including structural if allowed to grow unchecked (I have experience of this).

What I see of the response to knotweed is that everyone is absolutely certain they would not buy a house that has knotweed, until they find a house that they love with knotweed in the garden. Then it’s about a pragmatic response to a) how much knotweed, b) the history of knotweed, c) how treatable the knotweed is.

I would say proceed with caution, with your eyes open, but it’s not an absolute dealbreaker.

I'm amazed at the hysterical responses to JK on here too....

Same. Not especially near the house? Get an insurance backed guarantee treatment plan and jobs a good un.

I live in an area where several houses have knotweed, especially those near a little brook, so I assume it is in some way related to the watercourse

It will be using the watercourse greenery as a corridor to move along. Easier than moving thru gardens with fences and humans who kill it.

Thanks again everyone - I’ve been reading about knotweed all weekend! Came across this which might be of interest to others in my situation, suggests that 3m may be a more appropriate “high risk” distance than 7m and that it would be beneficial to shift to viewing this as an invasive plant in terms of its damage to the environment/other plants rather than the enormous risk it is perceived to pose to buildings, in this country. I can’t say I’ve read the whole thing but the introduction and conclusions are interesting.

randd.defra.gov.uk/Document.aspx?Document=14914_2019-20-RPAKnotweedFinalReport.pdf#page106

"What I see of the response to knotweed is that everyone is absolutely certain they would not buy a house that has knotweed, until they find a house that they love with knotweed in the garden."

This in spades! When we found our house our main worry was whether the mortgage valuation person would notice the knotweed in case it interfered with the sale! Luckily very little of it was visible by November, and he obviously wasn't a botanist . I find it horrifying that they might have refused to mortgage it on such a ridiculous basis. Our house is more likely to be destroyed by meteorite than knotweed.

@Bluebird76 were you subsequently able to get rid of the knotweed?

The more I read about it the more I see that it is in fact quite manageable and the big issues come about if it is neglected or if people go about getting rid of it in the wrong way and cause more spread.

But other people's reaction to it is still a huge issue that will probably affect us when we come to move, if we go ahead with this one.

Sorry @Bluebird76 realised you already told me about your knotweed success!

We had knotweed in our garden and managed to get rid of it, this was over 5 years ago and it's not come back. I agree with a pp about people being hysterical, I also thought attitudes to it by mortgage lenders were meant to be changing.

I should say with just dedication and round up - no professionals involved (it was a small patch)

@Freddiesgirl

I should say with just dedication and round up - no professionals involved (it was a small patch)

That's all professional use, I'm sure? There's no other treatment afaik. It's cheap and effective, you don't need professional involvement at all.

I’d run not walk away!

Knotweed has such a hilariously scary out-of-proportion reputation :D. I'd happily buy a house whit it growing within. uncontained Bamboo is wayy worse.
OP, your main issue is that it spreads between the neighbours - they have to be on side if it is to be dealt with, or you have to be willing to hope the fence & perform covert darkness weedkiller raids.

We discovered a big patch of knotweed on the neighbouring patch of wasteland at the bottom of our house when we moved in (yet another thing our seller never told us, including the underpinning she did ).
We got rid of the lot over a course of two years by injecting every plant with industrial glyphosate. That was 9 years ago, no sign since. My neighbour noticed a couple of plants at the bottom of his garden last year so he doused them with a load of chemicals and again they haven’t come back so far.

We have knotweed in our garden. The neighbours in the flat above have been here for 30 years. The Japanese knotweed has been here as.long as they can remember and.....nothing has happened. Literally nothing. There are two small patches. We pull it up when we see it and it hasn't got worse, it's just still the same two tiny patches.in fact, we completely forgot about it until recently as we want to move.

We are getting a treatment plan in place purely because we want to sell, not because it is needed. The treatment company admitted it's money for old rope and we are basically paying for the Certificate as it isn't the massive issue people seem to think it is.

Getting rid of it is making some people a lot of money...my partner says it would cost around £30 in industrial strength weedkiller....he says each stem has to be injected with the chemical so it is time consuming but thats about it...he honestly cannot see why it causes so much drama.

@myusernamewastakenbymem I read that somewhere. The companies just use ordinary weed killer you can buy anywhere but because they are approved by some trade body, they charge £2k and provide the Certificate that buyers need to see.