Our club has a river which is heavily contaminated with Japanese Knotweed. It would be interesting to know how many other fisheries are ruined by this impregnable weed.We are working with the fishery board and trust to try and eradicate it but cost a fortune and very time consuming

Birmingham City Council commissioned a consultant to look into eradicating it on their land or land within their remit and the upshot was it would cost too much and be too labour intensive to be viable. Quite a devastating plant.

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Around the steel no tortur'd worm shall twine,
No blood of living insect stain my line;
Let me, less cruel, cast feather'd hook,
With pliant rod athwart the pebbled brook,
Silent along the mazy margin stray,
And with fur-wrought fly delude the prey

It's a huge problem along the Taff and rivers in South Wales generally,it's spread and tenacity is apparently irreversible there unless we can buy a few million Japanese caterpillars with all of the implications that pitting alien species versus alien species carries - Godzilla meets Bugs.

A four or five acre fallow field bordering the Taff is completely overrun with the stuff which presents a huge cost for anyone planning to farm or develop the site in the future - I hate walking through it. I wouldn't say the fishery is ruined but the eight foot tall border of knotweed that exists in some areas of the lower river makes access very awkward without a machette (literally) and of course it completely erradicates beneficial native species.

JK's getting a toe hold in West Wales now but the lack of concern is stunning. I hope to begin to reverse this decline in a small way over the next year or two with a demo project Insha'Allah but I'm afraid this will be peeing in the wind given the scale of the problem.

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Musha rig um du rum da

As big a problem as it is I dont think that introducing an alien predator to these shores is the answer.

Some scientists do though... BBC NEWS | Science & Environment | Predators could be superweed fix

The worst thing about JKW is it prevents anything, and I mean anything - even grass from growing underneath it. The end result being when the JKW dies back in the winter the river banks are dangerously exposed and susceptible to rapid erosion.

I'm reliably informed its still being sold at garden centers all across the UK!!..

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Before you cast the fly, make sure you can handle the fish! Vuoi imbrogliare? Poi Non competere! (If you want to cheat, then dont compete)

Had some JKW appear in my garden 3 years ago - a strong mix of this
Vitax SBK Brushwood Killer Concentrate 250ml [VITAX5BKA250] at www.CapitalGardens.co.uk :::
was spray applied on a calm day and it quickly killed the JKW.

No regrowth has occurred

Appreciate that it would be expensive to treat large area's this way.
But at least it works.

Tony

Anyone buying JKW from a garden centre must be bonkers; they can get it for free almost anywhere along the rivers of the South Wales M4 corridor, but once planted they'll come to regret it.

After I moved into my present home it took me years of regular cutting back to eradicate it from just a small area of my garden.

OB

Do not cut it back! Every last bit of it is viable and will recolonise. If cut back it is Controlled Waste and has to be disposed of in a licenced tip.

Cheapest, easiest and most cost effective way to deal with large stands is to spray with 10% Glyphosphate solution in September. With smaller stands it an be treated by injecting the same concentration directly into the stems, above the third node at any time of year.

On the Monnow, we have treated the whole catchment this year, for the first time, with the help of WUF.

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"The sun was so delightfully warm, and the stone, which had been sitting in it for a long time, was so warm, too, that Pooh had almost decided to go on being Pooh in the middle of the stream for the rest of the morning."

www.monnow.org

Walk along the river Lune at the Crook Of Lune (a well known beauty spot) and you will see all the banks coverd in Himalayan Balsam. This plant is also very invassive and takes over. When it dies back in the winter there is nothing left on the banks of the river. It grows to about 6-7ft in a matter of weeks. Fortunatly is is esaly pulled out of the ground but if left to flower it spreeds in a very short time. Also along the A6 passing Lancaster University the hedges are full of the plant it out grows through everthing and will even grow through, nettles and hawthorn. I do believe that along the river Kent voulenteers are trying to eradicate the plant.
Cheers Maxie