Japanese Knotweed - how to kill?

Wanderer78

Purple Mountain wrote:

Sorry for the ignorance but why is it so bad?

It's an evasive species, that kills off native species, and grows at an astonishing rate

my3cents

Purple Mountain wrote: »

Sorry for the ignorance but why is it so bad?

It propagates easily and once established takes over an area creating an ecological desert where nothing else can grow in its shade.

Control is difficult takes a long time and is very expensive.

Nekarsulm

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.

my3cents

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.

The digger can be part of the problem with Rhododendron Ponticum. Yes the stumps need digging up but if the branches haven't been cleared first then they get tracked in by the heavy machinery movement and take root creating new plants.

Thud

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.

https://www.zmescience.com/other/feature-post/mad-honey-deli-bal/

eoinmk2

after finding a patch in the grandfathers garden. disaster, but caught it early.

after spraying what should you do with the dead material? leave it where it is, remove it (cut it off without disturbing the soil), burn it?

Bass Reeves

eoinmk2 wrote: »

after finding a patch in the grandfathers garden. disaster, but caught it early.

after spraying what should you do with the dead material? leave it where it is, remove it (cut it off without disturbing the soil), burn it?

All the advice here is to leave it and watch for regrowths.

Mousewar

The council are saying now they're coming out to do an initial spray of the knotweed in the coming days before treating it extensively in Aug/Sept.
Is that...is that a good thing?

In other news, on the dart at killiney I can see Giant Hogweed growing - looks about 12 foot or so.

my3cents

Mousewar wrote: »

The council are saying now they're coming out to do an initial spray of the knotweed in the coming days before treating it extensively in Aug/Sept.
Is that...is that a good thing?

In other news, on the dart at killiney I can see Giant Hogweed growing - looks about 12 foot or so.

I think coming out now is a bit late I like to get an early spray before the plants get to full size (in May) and to keep them down so they recover a bit before September but aren't as tall as they would normally be.

At this stage the plants are full size and may not all recover fully to get a good dose in at the end of the season.

However just the fact the council is coming out even if it is at a less than ideal time does have some good points.

Firstly they will know where the plants are when it comes to spraying later and will probably find a few more stands of it that aren't on their lists. Secondly it does show they are doing something and anything is better than nothing. Thirdly they may not have enough trained operators to get around to all the outbreaks they have at the best time so will cover more if they start early.

Edit> Also we have no idea what herbicide they council are using. Roundup is the one where the recommendation is for the spray at the end of the season before it dies down others such as Icade are recommended for use earlier in the year. A long read but some very good info https://www.property-care.org/wp-content/uploads/2016/11/PCA-Invasive-Weed-Conference-2016_Dr-Daniel-Jones-presentation.pdf .

Mousewar

Well, the owner of the property across from me showed up last evening and took a hedge trimmer to it. He'd done basically all of it before I saw him and intervened. He had been sent all the info on it and chose to ignore it and take care of it himself. I at least stopped him from taking the cuttings to the dump and have asked the council to intervene.

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.