Japanese Knotweed - how to kill?

Markcheese

Gonna throw this in, a friend suggested grazing a patch with goats... I dunno whether they'll like it much but I've seen a tethered goat demolish a half acre of 10 foot tall briars in a couple of weeks... Wont stop them growing back... But would knock them back...

Chisler2

Nekarsulm wrote: »

Another problem with Rhododendrum is that while it has a mass of flowers that bees love, honey made from them is poisonous to the bees.
So when they use the honey food stocks in the winter it poisons them.
You have to dig Rhododendrum up with a digger, its trunks are twisted and convoluted and not suitable to machine harvesting.
Good firewood when seasoned, however.

I propose chipping the wood from rhodendendron I have taken out to spread as woodland paths through the garden and orchard.......an alternative to stone chippings which are noisy. Is there any risk that this wood (when well dried out and rotted down, then shredded fine) would send up shoots?

my3cents

Chisler2 wrote: »

I propose chipping the wood from rhodendendron I have taken out to spread as woodland paths through the garden and orchard.......an alternative to stone chippings which are noisy. Is there any risk that this wood (when well dried out and rotted down, then shredded fine) would send up shoots?

There should be no problem with that at all.

The problem is that forestry relies massively on heavy tractors and plant. If you use that in amongst rododendrum ponticum then you effectively plant cuttings of some of the material that gets smashed off.

If you chip it then you will have little or no suitable material to create cuttings and once they have been dried out a bit nothing will root anyway.

HeidiHeidi

Could anyone on here point me to an "official" or reliable online source of information on how to deal with this?


We have discovered a growth of this on a neighbour's land - it's on top of a retaining wall, and we're afraid that if it gets into the stones and weakens the wall, the whole lot might land in on top of us :eek:


Both houses are holiday houses, the owners of the other one live abroad as far as we can tell.


They say they're on it, but the dealings we've had with them so far (very few and brief) would suggest otherwise.


We'd like to send them a link or some other source of information which might wise them up to the seriousness of it.


We've given it one spray ourselves, but it's so thick and in such an awkward spot that I doubt it'll have much of an effect

wexie

HeidiHeidi wrote: »

Could anyone on here point me to an "official" or reliable online source of information on how to deal with this?

I might be mistaken but I think it's actually illegal to try to do it yourself because it's such nasty stuff and requires a very specialized approach. Local county council should be able to help or point you towards a professional

TomOnBoard

HeidiHeidi wrote: »

Could anyone on here point me to an "official" or reliable online source of information on how to deal with this?


We have discovered a growth of this on a neighbour's land - it's on top of a retaining wall, and we're afraid that if it gets into the stones and weakens the wall, the whole lot might land in on top of us :eek:


Both houses are holiday houses, the owners of the other one live abroad as far as we can tell.


They say they're on it, but the dealings we've had with them so far (very few and brief) would suggest otherwise.


We'd like to send them a link or some other source of information which might wise them up to the seriousness of it.


We've given it one spray ourselves, but it's so thick and in such an awkward spot that I doubt it'll have much of an effect

JK will undermine your wall(s)

This to learn:

https://www.rhs.org.uk/advice/profile?pid=218

This is from UK, but same principles are relevant. I'm not sure if there's anything similar here.

These to treat:

http://www.thejapaneseknotweedcompany.com/

HeidiHeidi

wexie wrote: »

I might be mistaken but I think it's actually illegal to try to do it yourself because it's such nasty stuff and requires a very specialized approach. Local county council should be able to help or point you towards a professional

County council website says they're treating roads (or they intend to), and basically infestations on private land are your concern.

TomOnBoard

Markcheese wrote: »

Gonna throw this in, a friend suggested grazing a patch with goats... I dunno whether they'll like it much but I've seen a tethered goat demolish a half acre of 10 foot tall briars in a couple of weeks... Wont stop them growing back... But would knock them back...

Goats are brilliant for scrub clearance, mowing IVY etc, so I'm not surprised they'd eat the JK. However, a few points arise:

1. Anything a goat eats is naturally absorbed into the meat and milk so if they're for eating or milking, I'd be very careful of what I'd let them eat;

2. If the goat has a feed of JK, it'll probably focus on the foliage and leave most of the stems behind. Just be aware that any undigested material will pass through the goat's system and may be spread through droppings. Also, chewings dropping out of the mouth at the site of the JK plant are another potential source of spreadable pieces of plant. Personally, I'd prefer to see this stuff dealt with in a controlled and well-planned manner on a multi-year basis, because it is highly unlikely it'll be cleared up in any single year.

wexie

HeidiHeidi wrote: »

County council website says they're treating roads (or they intend to), and basically infestations on private land are your concern.

sorry

HeidiHeidi

wexie wrote: »

sorry

So am I!


I've emailed them anyway asking if they've any interest in knowing about it and can they help in any way. I won't be holding my breath!

wexie

HeidiHeidi wrote: »

So am I!


I've emailed them anyway asking if they've any interest in knowing about it and can they help in any way. I won't be holding my breath!

Well if you get stuck I have a friend who is an environmental consultant and does a lot of work with knotweed for the likes of Irish Water and road works

Think he really only does east coast though and he's pretty busy but he might know someone else that could help.

you can contact him here

* hope this is allowed

HeidiHeidi

wexie wrote: »

Well if you get stuck I have a friend who is an environmental consultant and does a lot of work with knotweed for the likes of Irish Water and road works

Think he really only does east coast though and he's pretty busy but he might know someone else that could help.

you can contact him here

* hope this is allowed

Thanks a million for that - but the problem is it's not on our land so there's only so much we can do. We're hoping to prod the owners into actually tackling it, and if they don't then we'll have to consider our options.

TomOnBoard

HeidiHeidi wrote: »

Thanks a million for that - but the problem is it's not on our land so there's only so much we can do. We're hoping to prod the owners into actually tackling it, and if they don't then we'll have to consider our options.

What part of the country are you in?

my3cents

HeidiHeidi wrote: »

Thanks a million for that - but the problem is it's not on our land so there's only so much we can do. We're hoping to prod the owners into actually tackling it, and if they don't then we'll have to consider our options.

Just get on and do it. Tell the landowner what you are doing and if he objects point out in the nicest possible way that he'll be paying the full costs of cleaning up any damage it does to your property and for removing it from your property.

Costs are not big deal to actually get out and treat it yourself, the time it takes and the continued follow ups are where the labour costs are.

TomOnBoard

my3cents wrote: »

Just get on and do it. Tell the landowner what you are doing and if he objects point out in the nicest possible way that he'll be paying the full costs of cleaning up any damage it does to your property and for removing it from your property.

Costs are not big deal to actually get out and treat it yourself, the time it takes and the continued follow ups are where the labour costs are.

Do not do this without some agreement with the owners. I fell badly foul of some French folks who had a property in Ireland and I had to repair a wall on a boundary. They were in Paris and I ended up having to deal with sh!tty legal letters for entering onto their property to fix the wall. I was doing a good deed; I couldnt contact them, and I got nothing but arrogant abuse afterwards. Never again!

twofish101

I know it Wales but how long before it crosses over to this side of the pond www.transport-network.co.uk/Network-Rail-loses-Japanese-knotweed-appeal/15151

wexie

twofish101 wrote: »

I know it Wales but how long before it crosses over to this side of the pond www.transport-network.co.uk/Network-Rail-loses-Japanese-knotweed-appeal/15151

Before what crosses over this side of the pond? Japanese knotweed is all over the country already?

my3cents

twofish101 wrote: »

I know it Wales but how long before it crosses over to this side of the pond www.transport-network.co.uk/Network-Rail-loses-Japanese-knotweed-appeal/15151

It swims with the fishes Honest. Where the roots get washed out of river banks here or the UK then they wash out to sea and can root where they wash up. So we can be infecting the UK with it and they can be infecting us.

I've treated a few clumps along the strand where I live and I often see lumps of root washed up.

twofish101

wexie wrote: »

Before what crosses over this side of the pond? Japanese knotweed is all over the country already?

I'm well aware of the infestation, I work for a company managing it, but this court ruling makes the landowner liable for the damage the weed has done to the neighbours.

wexie

twofish101 wrote: »

I'm well aware of the infestation, I work for a company managing it, but this court ruling makes the landowner liable for the damage the weed has done to the neighbours.

Ah okay.

I'm not too sure how I feel about it to be honest. On the one hand it seems to have gotten pretty bad in the UK.

On the other, if you have an issue on your land, are aware of it, refuse to deal with it and it consequently becomes your neighbour's issue I can see how they'd be a bit miffed.

my3cents

twofish101 wrote: »

I'm well aware of the infestation, I work for a company managing it, but this court ruling makes the landowner liable for the damage the weed has done to the neighbours.

Sound ruling as far as I can see.

You let it grow and don't control it then you are responsible.

Its not that difficult to control it to the extent that its not expanding its territory. Getting rid of it totally is of course another kettle of fish.

Good loser

Good loser wrote: »

A smallish clump I sprayed with Grazon last year came again this year and last week I decided to pull it manually, which was surprisingly easy to do. All came up except one, the biggest clump, which I just broke down.
Underground there is a mass of peat like material - small or large depending on the mass overground. The outlying plants were singletons but centre ones had 4 to stalks.
Will go back with Grazon later in year.

Looked at site again yesterday.


Much reduced entity. Sorry now I didn't go harder at biggest clump.


Pulled what was there again - harder because of drought.


Ferns, briars etc alongside were shading the edges of the JK.

my3cents

Good loser wrote: »

Looked at site again yesterday.


Much reduced entity. Sorry now I didn't go harder at biggest clump.


Pulled what was there again - harder because of drought.


Ferns, briars etc alongside were shading the edges of the JK.

Why didn't you go back and spray it again with Grazon?

Grazon is probably the better chemical to be using at this time of year than Roundup anyway.

Good loser

my3cents wrote: »

Why didn't you go back and spray it again with Grazon?

Grazon is probably the better chemical to be using at this time of year than Roundup anyway.

Will do that. Should only take a minute.

my3cents

Good loser wrote: »

Will do that. Should only take a minute.

We are only about 6 weeks off the start of the ideal time for spraying with glyphosate so if you don't want the expense of using Grazon you can always wait.

Good loser

my3cents wrote: »

We are only about 6 weeks off the start of the ideal time for spraying with glyphosate so if you don't want the expense of using Grazon you can always wait.

I have the Grazon. The remnants are really small and weak looking.

my3cents

Good loser wrote: »

I have the Grazon. The remnants are really small and weak looking.

I'd use because it does a good job but its expensive.

Keep an eye on those remnants because its not unknown for them to come back to life in a year or so.

monty_python

Markcheese wrote: »

Gonna throw this in, a friend suggested grazing a patch with goats... I dunno whether they'll like it much but I've seen a tethered goat demolish a half acre of 10 foot tall briars in a couple of weeks... Wont stop them growing back... But would knock them back...

Friend of mine has a small holding with a stream on the boarder of it.
Her side of the boarder has no knotweed and the other side is infested with it. She keeps goats and sheep. The goats work.

my3cents

monty_python wrote: »

Friend of mine has a small holding with a stream on the boarder of it.
Her side of the boarder has no knotweed and the other side is infested with it. She keeps goats and sheep. The goats work.

You mean you can't see it. I've a few bits that I didn't get a good kill on 10 or more years ago and I've been cutting them with a mower 20-30 times a year since, they never make more than a leaf or two but are still there if you know what to look for.

Stop grazing the area and I expect if it was there it will come back. No reason not to have JK on one side of a river and none on the other. There are some spots up our river where it is only on one side.

Mousewar

Does anyone have a link to a good authorative source on treating Japanese knotweed? In particular, one that explains:
A) That spraying in August/September is the best course of action.
Why August/September are the months to do it.
C) The perils of any attempt to dig it out.

Basically, the landlord of the house opposite me returned yesterday and sprayed Roundup. (I know it's August but is it a tad early?) He seemed annoyed about waiting until August like I told him last month and said he thinks we should spray it all year round. He also said he plans to dig it out. He seems unwilling to accept my explanation for a, b, and c above so I'd like to send him a source he can't argue with.

TomOnBoard

Mousewar wrote: »

Does anyone have a link to a good authorative source on treating Japanese knotweed? In particular, one that explains:
A) That spraying in August/September is the best course of action.
Why August/September are the months to do it.
C) The perils of any attempt to dig it out.

Basically, the landlord of the house opposite me returned yesterday and sprayed Roundup. (I know it's August but is it a tad early?) He seemed annoyed about waiting until August like I told him last month and said he thinks we should spray it all year round. He also said he plans to dig it out. He seems unwilling to accept my explanation for a, b, and c above so I'd like to send him a source he can't argue with.

Will he argue with Monsanto's own guide for JK eradication?

THE CONTROL OF JAPANESE KNOTWEED WITH ROUNDUP PRO BIACTIVE

Mousewar

Thanks.
I think he'd argue with anything. I've explained why Aug/Sept is the best time to spray twice now. First time, in July, he said I was wrong and they only say that because Aug/Sept are "dry months" and it's best to spray when it's dry and since it was the middle of a drought (in July) that was a great time to attack it. Second time (yesterday) he said they just say Aug/Sept because they are the months of highest growth.
Anyway, I think he's just using regular roundup. Is that less useful or totally useless?

TomOnBoard

Mousewar wrote: »

Thanks.
I think he'd argue with anything. I've explained why Aug/Sept is the best time to spray twice now. First time, in July, he said I was wrong and they only say that because Aug/Sept are "dry months" and it's best to spray when it's dry and since it was the middle of a drought (in July) that was a great time to attack it. Second time (yesterday) he said they just say Aug/Sept because they are the months of highest growth.
Anyway, I think he's just using regular roundup. Is that less useful or totally useless?

I cant tell you whats the difference between them. Im sure someone else will.

The crucial thing is that UNDER NO CIRCUMSTANCES should he attempt to dig it out because much of the plants will still be alive, even if the Roundup appears to kill the visible stems and foliage.

Markcheese

The big issue with digging the plany out is where do you put what you've dug out?? Digging out the main stools isn't going to make much difference to the plants ability to regrow on its current site...

Purple Mountain

I know absolutely nothing about this plant but see it popping up locally on ditches and the signs have gone up beside them.
My mother is of an age where she says (she thinks) she remembers them in her childhood (although she calls it bindweed) and that there was never a panic over it, it was just left grow and nothing disastrous happened??

TomOnBoard

Purple Mountain wrote: »

I know absolutely nothing about this plant but see it popping up locally on ditches and the signs have gone up beside them.
My mother is of an age where she says (she thinks) she remembers them in her childhood (although she calls it bindweed) and that there was never a panic over it, it was just left grow and nothing disastrous happened??

They're two different plants, although their leaves do look somewhat similar. being heart-shaped. JK is waaaaay stronger than BW. JK smothers an area and is self-supporting while BW grows by clinging to another plant or structure and climbing up.

They're both invasive and each requires multiple doses of Glyphosate to kill them, but while BW might be a 3 on a scale of 1 to 10 in terms of damage it can do to other plants, JK is a 10. BW is a 0 in terms of potential structural damage it can do, while JK is a 9 or 10.

Put another way, BW is George W Bush and JK is Trump...

Purple Mountain

TomOnBoard wrote: »

They're two different plants, although their leaves do look somewhat similar. being heart-shaped. JK is waaaaay stronger than BW. JK smothers an area and is self-supporting while BW grows by clinging to another plant or structure and climbing up.

They're both invasive and each requires multiple doses of Glyphosate to kill them, but while BW might be a 3 on a scale of 1 to 10 in terms of damage it can do to other plants, JK is a 10. BW is a 0 in terms of potential structural damage it can do, while JK is a 9 or 10.

Put another way, BW is George W Bush and JK is Trump...

Mam made the comparison to ivy that takes over and smothers other plants/trees and yet there's no panic about it.
I'm obviously not getting the whole JK debacle.

my3cents

Purple Mountain wrote: »

Mam made the comparison to ivy that takes over and smothers other plants/trees and yet there's no panic about it.
I'm obviously not getting the whole JK debacle.

The issue is that it is a non native species, the ease with which it spreads the speed with which it gets established (taking over completely and creating a mono-culture) and the difficulty of getting rid of it.

http://invasivespeciesireland.com/species-accounts/established/terrestrial/japanese-knotweed .

orm0nd

Mousewar wrote: »

Thanks.
I think he'd argue with anything. I've explained why Aug/Sept is the best time to spray twice now. First time, in July, he said I was wrong and they only say that because Aug/Sept are "dry months" and it's best to spray when it's dry and since it was the middle of a drought (in July) that was a great time to attack it. Second time (yesterday) he said they just say Aug/Sept because they are the months of highest growth.
Anyway, I think he's just using regular roundup. Is that less useful or totally useless?

best time to spray most weeds is when they are in maximum foliage just b/4 they flower thus to prevent the spread of seeds and further re infestation

maximum foliage means more chemical is taken and travels further into the root system

HOWEVER JK does not spread through fallen seeds , instead it spread through bits of roots carried in clay etc
It can lie dormant in same and suddenly burst into growth decades later, I have first hand experience of this

cutting or topping will spread it more , cos the roots will travel further underground and I've seen it actually burst up a tarmac drive way, again it may take decades

I've meant to post some pics here of sites we've treated but haven't got to visit them yet due to the drought we are otherwise occupied

regular roundup or garlon will work initially but will not give full long term control

good idea to add a sticky or wetting agent (presto or wetcit etc,) to ensure better adhesion to the leaves especially after the long dry spell

Good loser

my3cents wrote: »

I'd use because it does a good job but its expensive.

Keep an eye on those remnants because its not unknown for them to come back to life in a year or so.

Did the grazon Friday.


Residual knotweed is small and spindly - easily sprayed -the pulling worked a treat.

my3cents

Good loser wrote: »

Did the grazon Friday.


Residual knotweed is small and spindly - easily sprayed -the pulling worked a treat.

I've just got my hands on some Grazon and I'm torn between using it now or waiting for another few weeks and hammering it with Roundup.

Its tricky site (not even mine but its near enough to be worth my while keeping it under control) by a river with steep banks so I have to spot weed the bank and a good way back from it with Roundup anyway as the Grazon is toxic to anything in the river and obviously has no clearance for use near water. For that reason I'm going to try and hold out and stick with the Roundup.

TomOnBoard

Good loser wrote: »

the pulling worked a treat.

I'm sure you're a lovely man, but Jaze I'm struggling to give the benefit of the doubt here...

EITHER you're having a laugh at the rest of us who have explained repeatedly that this stuff should neither be pulled nor cut, in accordance with scientific/botanical advice.... OR

This attitude is just proving the old adage that "There are none so blind as those who WILL not see!!"

Good luck with your rejection of scientific opinion... Regrettably, there's a lot of that about the place these days... So you're not alone in your incredulity and skepticism. Unfortunately!!

Nekarsulm

my3cents wrote: »

I've just got my hands on some Grazon and I'm torn between using it now or waiting for another few weeks and hammering it with Roundup.

Its tricky site (not even mine but its near enough to be worth my while keeping it under control) by a river with steep banks .

Wouldn't a decent size drone be able to handle a miniature sprayer (2 litres or so) with a small ni-cad battery, pump and nozzle or two?
The down draft would help as well, I expect, and a dash of food colouring in the Roundup would help avoid missing bits.

Twat-Badger

Nekarsulm wrote: »

Wouldn't a decent size drone be able to handle a miniature sprayer (2 litres or so) with a small ni-cad battery, pump and nozzle or two?
The down draft would help as well, I expect, and a dash of food colouring in the Roundup would help avoid missing bits.

In order to operate a drone capable of lifting a 2kg payload (such as 2litres of Roundup) you would need to be approved and registered with the IAA first.

Good loser

TomOnBoard wrote: »

I'm sure you're a lovely man, but Jaze I'm struggling to give the benefit of the doubt here...

EITHER you're having a laugh at the rest of us who have explained repeatedly that this stuff should neither be pulled nor cut, in accordance with scientific/botanical advice.... OR

This attitude is just proving the old adage that "There are none so blind as those who WILL not see!!"

Good luck with your rejection of scientific opinion... Regrettably, there's a lot of that about the place these days... So you're not alone in your incredulity and skepticism. Unfortunately!!

If the pulling worked, as it unquestionably did here, then the science will have to adjust!

The JK is/was on the roadside outside my road ditch and beginning to encroach on the ditch.

my3cents

Good loser wrote: »

If the pulling worked, as it unquestionably did here, then the science will have to adjust!

The JK is/was on the roadside outside my road ditch and beginning to encroach on the ditch.

The question really is what did you pull and how did you dispose of it?

Mousewar

If you spray the stuff now and it's dead come end of september, what do you do with it then? Take it up and dispose or leave it there? Will it eventually wither to nothing?

99nsr125

Mousewar wrote: »

If you spray the stuff now and it's dead come end of september, what do you do with it then? Take it up and dispose or leave it there? Will it eventually wither to nothing?

Well, one of the methods is to treat it like hazardous wastes and for everything to be industrially incinerated and reburied 5 metres down as road base or such

Here you would leave it to make sure it is dead for sure and let it decay away if it is all dead

No ground disturbance
No accidental spreading
No contaminated equipment
Vastly cheaper

my3cents

When it dead its fairly obvious its dead. I often knock it over with a sythette during the winter just to make it easier to get to any regrowth in the spring.

Mousewar

Grand.
Still no word from the council on what to do with the big bag of the stuff he cut away last month. Still sitting in a bag in his garden. Don't know what to tell him, he'll probably just take it to the dump soon.