Japanese Knotweed ?

Usjes

Hi,

My mother got a gardener in to do the garden and he told her that she had JK. It's growing only 10 feet from the house and about 5 feet from her neighbour's extension. So I did a bit of googling and I'm almost certain its not JK. While it does have some cosmetic similarities, the flowers look the wrong size, the stalks are the wrong shape and colour etc. But all of these are subjective so I was looking for something which would prove for certain that it can't be JK. So reading about JK it seems that there are only female plants in the UK and Ireland so it only spreads via cuttings or root fragments. The plant in her garden currently has bunches of purple/black berries up to 1cm in diameter. Is this the definitive proof ? Or can JK have berries on it ?

Thanks,

Usjes.

Water John

Haven't seen berries on ours, must check. Like you, think its JK. See the residents of Glounthaune in Cork got special needles to inject weed killer into it. Cost about €300.
Best way to get rid of it.

my3cents

Some of the best simple guides are

Japanese knotweed http://www.fisheriesireland.ie/invasive-species-1/242-japanese-knotweed-id-sheet-1
Himalayan knotweed http://www.fisheriesireland.ie/invasive-species-1/241-himalayan-knotweed-id-sheet-1
Giant knotweed http://www.fisheriesireland.ie/invasive-species-1/239-giant-knotweed-id-sheet-1
Hybrid knotweed http://www.fisheriesireland.ie/invasive-species-1/237-bohemian-knotweed-id-sheet-1

Three spp and a hybid the fist one Japanese Knotweed, Fallopia japonica is the main one causing the weed problem but the others are around.

lazybones32

Usjes wrote: »

Hi,

My mother got a gardener in to do the garden and he told her that she had JK. It's growing only 10 feet from the house and about 5 feet from her neighbour's extension. So I did a bit of googling and I'm almost certain its not JK. While it does have some cosmetic similarities, the flowers look the wrong size, the stalks are the wrong shape and colour etc. But all of these are subjective so I was looking for something which would prove for certain that it can't be JK. So reading about JK it seems that there are only female plants in the UK and Ireland so it only spreads via cuttings or root fragments. The plant in her garden currently has bunches of purple/black berries up to 1cm in diameter. Is this the definitive proof ? Or can JK have berries on it ?

Thanks,

Usjes.

The purple 'berries' make it sound like leycesteria formosa

Water John

3cents, good pics there. Bit confused, I'd say mine is No 1 but the flowers are largely pink. Maybe that is acid soil?
No fruit

my3cents

Water John wrote: »

3cents, good pics there. Bit confused, I'd say mine is No 1 but the flowers are largely pink. Maybe that is acid soil?
No fruit

I've seen a lot of Japanese knotweed and tbh I don't think I've ever noticed pink flowers White/creamy is how I'd describe Japanese knotweed.

Japanese knotweed is all female in Ireland all from a single plant (a clone) so no fertile seed which is a good thing the other species I think can set viable seed here?

Fallopia japonica is a member of the Polygonum family (knotweeds) and I'm fairly sure there are some with pink flowers one that springs to mind is Persicaria Orientale which is a tiny bit similar but its an annual.

Another old name for Japanese knotweed is Polygonum cuspidatum.

Leaf sizes and dimensions are fairly consistent so measuring a few mature leaves can narrow down which is which.

Water John

Thanks, that might be it. It dies back totally every year.

Genghis Cant

my3cents wrote: »

Leaf sizes and dimensions are fairly consistent so measuring a few mature leaves can narrow down which is which.

Just on this topic. Be careful as there's also Giant Knotweed and Bohemian Knotweed which is a cross between Giant and Japanese.
So leaf size may not be a good guide.

This time of the year Japanese Knotweed is in flower and it leaves it easier to identify. Though if it's being treated with sprays it may suppress flowering.
It's a nasty dose this knotweed.

my3cents

Genghis Cant wrote: »

Just on this topic. Be careful as there's also Giant Knotweed and Bohemian Knotweed which is a cross between Giant and Japanese.
So leaf size may not be a good guide.

This time of the year Japanese Knotweed is in flower and it leaves it easier to identify. Though if it's being treated with sprays it may suppress flowering.
It's a nasty dose this knotweed.

No its ideal, I was suggesting that it was a good way to distinguish between the 4 types of Japanese knotweed.

There is a good side by side comparison here http://www.japaneseknotweedireland.ie/invasive-species/japanese-knotweed-knotweed and the pdf's I linked to above have similar comparisons and sizes.

I find JK easiest to identify from a distance of about 100m or more, there is nothing I know native to Ireland that has quite that same green colour that sort of glows (smugly) in comparison to other plants around it.

Now is the time to treat JK with as much ghphosate as you can get on it. When the leaves drop off later the plant takes all the available nutrients from the leaves down into the root system and the glyphosate goes with them making for a better kill.

Genghis Cant

my3cents wrote: »

No its ideal, I was suggesting that it was a good way to distinguish between the 4 types of Japanese knotweed. s

Ok. I missed that bit in your post. Where you mentioned it being a good way to distinguish between the different types of knotweed.

my3cents

Genghis Cant wrote: »

Ok. I missed that bit in your post. Where you mentioned it being a good way to distinguish between the different types of knotweed.

It didn't read very well and its a bit of a stretch to expect you to have opened all 4 links and downloaded all 4 pdf guides to see what I was on about.

Genghis Cant

my3cents wrote: »

It didn't read very well and its a bit of a stretch to expect you to have opened all 4 links and downloaded all 4 pdf guides to see what I was on about.

I didn't open any of them. I have plenty of literature here about knotweed, I'm very familiar with it. I just missed the bit in your post.

Unfortunately we've lost the war on knotweed. I think we're over ten years late. I see it exploding along river corridors as well as roadside verges.

There's still not near enough being done to control it.

Nekarsulm

There is a clump of it along a boreen I use. Been growing three years now. Instead of running after the Council and hoping they take action, should I hit it with a strong solution of Round-up myself?
Its in flower now, and only covers the area of a kitchen table yet.
Or is there something better to spray on it?
Even if it just checks it for this year.

Water John

Good time to spray it Nekar as it will take it down to the roots as it dies back as some one posted earlier.

Nekarsulm

Cheers!
Just noticed a whole other thread about it.
Is injecting each stem with 20ml of Roundup Bi-active at a 1:1 strength before spraying still best practice?
A sheep vaccination auto injector would be ideal for the job, i think.

my3cents

Nekarsulm wrote: »

There is a clump of it along a boreen I use. Been growing three years now. Instead of running after the Council and hoping they take action, should I hit it with a strong solution of Round-up myself?
Its in flower now, and only covers the area of a kitchen table yet.
Or is there something better to spray on it?
Even if it just checks it for this year.

I spray it fully aware that what I am doing is in effect illegal.

Still I would't want to stop anyone

For me to tell you to use a strong solution of Roundup would also be technically illegal. Read the label However you will need to use the stronger rates and wet as much of the foliage as possible to get the best effect.

The councils do however seem to have recently taken on board that they have some responsibility for controlling Japanese knotweed so if informed they may do something.

Water John

I think the injecting is in place of spraying. Don't think you have to inject each stalk as you'll find a whole lot go back to the one root?
The injector costs €300.

my3cents

Nekarsulm wrote: »

Cheers!
Just noticed a whole other thread about it.
Is injecting each stem with 20ml of Roundup Bi-active at a 1:1 strength before spraying still best practice?
A sheep vaccination auto injector would be ideal for the job, i think.

I'd disagree on the rate I use a lower strength but that will work very well. I'd be a little concerned if the sheep vaccination auto injector was ever used on sheep again? I use a metal wire to make a whole in the stem then a syringe like thing used in cooking to inject/tenderise meat - again an off label use Edit> This is what I use a Kitchen Craft Flavour Injector - £1.99.

For small isolated clumps injecting really is the way to go and can get a 100% kill if you get enough stems and are just a bit lucky (depends I think on how established the underground parts of the plant are).

Day Lewin

Nekarsulm wrote: »

There is a clump of it along a boreen I use. Been growing three years now. Instead of running after the Council and hoping they take action, should I hit it with a strong solution of Round-up myself?
Its in flower now, and only covers the area of a kitchen table yet.
Or is there something better to spray on it?
Even if it just checks it for this year.

Yes: probably the most sensible thing you could do.
Watch the place and re-spray when it reappears (it will)
Best way to control a small clump, much quicker than waiting for someone "official" to get around to it.

Nekarsulm

Well I wont be spending 300 notes for an injector for a clump on the public road, anyway

Something like this would be my plan....



They are given away by some chemical companies with the vaccination, so no problem getting rid of it after week killer used.

Or i'll just use the knapsack. Two minutes will treat it, hop out of the jeep, spray, and gone ....

Nekarsulm

Biggest risk of the injector would be getting into a rhythm of "Grab stalk, stab, squeeze trigger" over and over again. Till you inject yourself with round-up ....

my3cents

Nekarsulm wrote: »

Well I wont be spending 300 notes for an injector for a clump on the public road, anyway

Something like this would be my plan....



They are given away bysome chemical companies with the vaccination, so no problem getting rid of it after week killer used.

To save you some grief I'll tell you now the needle will get blocked very quickly so use a bit of wire to punch a hole in the stem first, cocktail sticks and toothpicks will also do the job.

I go for the first decent sized section of stem (it is hollow and compartmentalised like bamboo) a couple up from the base. I them make a hole in the middle and inject about 20ml into the hole.

the goon

Would I be right in saying the attached pic is Japanese knotweed? Spotted in Cork city. It looks like it has been cut back,which, I thought was not a good idea with this stuff?

Water John

Yeah, should not be cut. Glounthaune parish found 80 locations.

Usjes

lazybones32 wrote: »

The purple 'berries' make it sound like leycesteria formosa

Thanks lazybones, there are a lot of replies in the thread but yours is the only one that actually came close to addressing my question; Can JK have berries ???
The above pictute is the plant in question and I had already decided its most likely identity was 'Himalayan Honeysuckle', still given that JK is such a harmful plant, it would be nice to have a difinitive way of ruling out Jk. ie. that it is not possibe for JK to produce berrries (in this country any rate).

Water John

Don't know about it fruiting, but the leaf there doesn't look like JK.

my3cents

Usjes wrote: »

Thanks lazybones, there are a lot of replies in the thread but yours is the only one that actually came close to addressing my question; Can JK have berries ???
The above pictute is the plant in question and I had already decided its most likely identity was 'Himalayan Honeysuckle', still given that JK is such a harmful plant, it would be nice to have a difinitive way of ruling out Jk. ie. that it is not possibe for JK to produce berrries (in this country any rate).

No berries the three winged seeds hang down in racemes, but I have never noticed them, maybe because the plants are all female and there are no male plants in Ireland.

https://extension.umass.edu/landscape/weeds/polygonum-cuspidatum has a good picture of the seeds, note Ploygonum cuspidatum is an old name for what is now called Fallopoia japonic - Japanese knotweed.

the goon

Water John wrote: »

Yeah, should not be cut. Glounthaune parish found 80 locations.

Wow, can't believe there is such a disregard for the impact of this stuff. I know resources are always an issue but not addressing this now can only have negative and harmful repercussions long term

Nekarsulm

http://cavancoco.ie/invasive-species.htm

my3cents

Nekarsulm wrote: »

http://cavancoco.ie/invasive-species.htm

Think all/most of the coco's have some info online now I've been quoting cork coco's pdf on JK for a few years now http://www.corkcoco.ie/co/pdf/786446050.pdf .

Achasanai

the goon wrote: »

Wow, can't believe there is such a disregard for the impact of this stuff. I know resources are always an issue but not addressing this now can only have negative and harmful repercussions long term

I would imagine ignorance plays a large part in it too. The average person who sees this growing somewhere on their property or on a road side probably thinks they're doing a good deed in trimming it down, but just isn't aware that they are doing so much harm.

The other side of the issue is the lack of a nationwide plan to deal with it. Nekarsulm posted a link to (I think) Cavan Co Co where there is a clear method of reporting knotweed growth (whether anything is actually done about it is another matter) but I have found it quite difficult to find who to report sightings in Dublin. I found a place to fire off a form, but no idea who it's going to or whether anything will be done about it.

Nekarsulm

Yeah, its Cavan Co.Co.
They actively attacked the problem on a streatch of road near Kilmore Cathedral. Posted signs in July or August last year prohibiting flail cutting of the clumps. Then chemically treated them. This year only a few shoots appeared, so they will hopefully hit them again, as per their own web site advice.

However, they never went near several other highly visible infestations along the Ballinagh road, about two miles away. So its hard to know what their overall plan is.

Water John

Hopefully, there doing it as a pilot.
I think the LA working with each local community as in Glounthaune is the way to go. Identify all sites in an area and eradicate.

my3cents

Nekarsulm wrote: »

Yeah, its Cavan Co.Co.
They actively attacked the problem on a streatch of road near Kilmore Cathedral. Posted signs in July or August last year prohibiting flail cutting of the clumps. Then chemically treated them. This year only a few shoots appeared, so they will hopefully hit them again, as per their own web site advice.

However, they never went near several other highly visible infestations along the Ballinagh road, about two miles away. So its hard to know what their overall plan is.

They probably are tackling the problem by putting one guy on the job. That keeps the cost down while allowing the coco to say they are taking positive action.

From the coco point of view anyone spraying has now to be trained and qualified.

Nekarsulm

my3cents wrote: »

I spray it fully aware that what I am doing is in effect illegal.

Still I would't want to stop anyone

For me to tell you to use a strong solution of Roundup would also be technically illegal. Read the label However you will need to use the stronger rates and wet as much of the foliage as possible to get the best effect.

The councils do however seem to have recently taken on board that they have some responsibility for controlling Japanese knotweed so if informed they may do something.

After 1 week.



After 2 weeks.



Three weeks after spraying.

my3cents

Was that you spraying or the council? If you what did you use and for the record what rate.

Anyone reading this now is a really good time before the leaves drop to be spraying Japanese Knotweed with glyphosate.

Nekarsulm

That was me spraying.
Clump is on the verge of a little by-road.
Roundup BiactiveXLA
60ml per litre of water in a knapsack.
Had it dripping wet
(That's Monsanto's recommended rate for Horsetail, Bracken and Knotweed. Don't think it actually works on Bracken at all, but its having an effect on the Knotweed)

EDIT: As far as I know, only Asulox works on Bracken. And it is only given a temporary licence for use by the Dept. Ag. every now and then.

Jcanty85

Hi folk, sorry to jump on this thread but I thought someone might be able to offer assistance. I was looking at a house today which has been vacant for quite some time and is very overgrown, it has very tall, branch like weeds growing up through the patio and all around the house, is this knotweed or some other sort of misery??
Appreciate any info,,

Nekarsulm

Looks like Sallies.
You should take a more close-up photo of the leaves and stem.
Photo 2 has Rhododendron on the right hand side, and looks like more sallies on the left. Np problem getting rid of either of those species.

http://www.irelandseye.com/aarticles/travel/nature/trees/willow/sally_rusty_willow/sally_rusty_willow.htm

Jcanty85

Is there any problem with these species growing up around foundations or anything? What would be the protocol for getting rid of these in the patio? Would they have to be dug out or just cut and sprayed?

Nekarsulm

The sallies are fairly shallow rooting, those are only a few years old. you could almost pull them up by the roots. Otherwise cut them off low and spray the stumps with brushwood killer or similar.

Jcanty85

So a sign has just appeared saying Japanese knotweed from the county council,, this house is up for auction soon and the open house in this week, just thinking what are the chances someone would put up a bogus sign? What sort of photos should I take to clarify?? Thanks for the help

my3cents

Jcanty85 wrote: »

So a sign has just appeared saying Japanese knotweed from the county council,, this house is up for auction soon and the open house in this week, just thinking what are the chances someone would put up a bogus sign? What sort of photos should I take to clarify?? Thanks for the help

My understanding is that the councils are only controlling JK on the road sides and on land they own. The signs they use seem to be be very similar and have the words, Japanese Knotweed Do Not Cut plus a site reference number and the name of the coco but not all the signs I have seen have the reference number filled in.

Article including a sign here

Edit> But if its a joke/scam I suspect its totally over the heads of the average Irish house buyer.

Nekarsulm

HA! I would be very suspicious!
I worked as an Estate Agent and that would be a manoeuver and a half!
Is the sale, do you know, taking place at the instruction of the Banks, or part of a family disagreement?
Never saw the Co.Council signpost private property. I recently alerted the local Co.Council about the locations of a number of growths and they have done nothing. Neither signposted nor sprayed.
Take a few close-up photos and let us have a look. (of the leaves, not the sign)

Once saw an auctioneer bring a friend to a site, with the friend dolled up in a suit and a "Woodies" reflective vest and wellington boots, with the objective of spurring on a reluctant (Corporate) bidder.
Worked too!

Edit. You could ring the relevant Co.Council and ask whoever is in charge of putting up these signs. I suspect you will find the Council are missing a sign somewhere!
If you are serious about buying this house, leave the sign where it is....

PS. A local Auctioneer sold an old listed building near me during the summer. UK based buyer, and I'm told he never visited the property, bought over the phone. I went for a nosey last week, and there is an ENORMOUS growth of KW. Ten foot high, must be growing for a decade. Bet his photo angles were carefully chosen to exclude that!

looksee

I am not seeing anything that could be Japanese Knotweed, though it may just be that it is not in the photos you have put up.

Nothing in the pics looks like a serious issue. The photos can be enlarged so that it is easy to see that you have a largish sycamore at the corner of the house, that would need to be killed asap. There are also briars, willow (sallies), and another sycamore under the window. Everything else is just weeds. The sycamores and the briars would be my biggest concern, but all the shrubby stuff should be killed off.

Edit: just figured out the second pic, still no JK but there does seem to be a large bush right beside the house wall that would need to be removed. If it is as close as it appears it might be worth doing a bit of investigation of the base of the wall.

recedite

Jcanty85 wrote: »

just thinking what are the chances someone would put up a bogus sign?

Pretty high I'd say. But download these guides and then look around the property for something that looks similar. If its there, it might not be beside the house.

my3cents wrote: »

Some of the best simple guides are

Japanese knotweed http://www.fisheriesireland.ie/invasive-species-1/242-japanese-knotweed-id-sheet-1
Himalayan knotweed http://www.fisheriesireland.ie/invasive-species-1/241-himalayan-knotweed-id-sheet-1
Giant knotweed http://www.fisheriesireland.ie/invasive-species-1/239-giant-knotweed-id-sheet-1
Hybrid knotweed http://www.fisheriesireland.ie/invasive-species-1/237-bohemian-knotweed-id-sheet-1

Three spp and a hybid the fist one Japanese Knotweed, Fallopia japonica is the main one causing the weed problem but the others are around.

my3cents

Did my last check around and spray today. Probably not necessary as all I was spraying was fasiated regrowth no more than a few centimeters high, but if its green its growing and can only "benefit" from a dose of glyphosate.

If a neighbor doesn't spray his bit I'll probably get to it as its too good an opportunity not to spray at this time of year.

mayo.mick

Interesting development in the UK,

"Landowners are being urged to put firm plans in place to control Japanese knotweed following a landmark court ruling."

http://www.hortweek.com/network-rail-japanese-knotweed-compensation-case-ruling-warrants-action/plant-health/article/1423531

my3cents

mayo.mick wrote: »

Interesting development in the UK,

"Landowners are being urged to put firm plans in place to control Japanese knotweed following a landmark court ruling."

http://www.hortweek.com/network-rail-japanese-knotweed-compensation-case-ruling-warrants-action/plant-health/article/1423531

That brings back memories, good old Horticultural Weekly, I used to have a subscription to it nearly 40 years ago when it was called Gardeners Chronicle & Horticultural Trade Journal, GCnHTJ for short.

Anyway back to the topic well spotted good article!

mayo.mick

my3cents wrote: »

That brings back memories, good old Horticultural Weekly, I used to have a subscription to it nearly 40 years ago when it was called Gardeners Chronicle & Horticultural Trade Journal, GCnHTJ for short.

Anyway back to the topic well spotted good article!

Hat tip to An Taisce!

.

magicbastarder

found this in the garden today. the garden has not had knotweed before, and has appeared in an area which had a leylandii hedge for decades (taken out about three years ago). it doesn't show any sign of the reddish stem that seems to be one of the identifiers, but i don't know what else it might be?
it was found about three foot from the corner at the end of the garden - we don't see any in the garden beside us, but that does not preclude it coming from the garden of the house behind us.