My mother (plant expert) spotted some Japanese Knotweed sprouting up on a patch of waste ground at the back of our site.
Is it something that should be reported to the council/environment agency? It isnt near anyones plot at the mo, but I seem to remember something about it being a notifiable pest. How bad is it? How far can it spread?
Notify them... before it does become a problem.
The law states:
"It is not an offence to have Japanese knotweed on your
land and it is not a notifiable weed. Allowing Japanese
knotweed to grow onto other peoples property may be
regarded as a private nuisance under common law, but
this would be a civil matter."
However your council may have a policy dealing with it so check their website. If the wasteground it is growing on is actually part of your allotment site then the council should definitely be notified.
The Environment Agency has various documents offering advice on controlling it.
http://www.environment-agency.gov.uk/homeandleisure/wildlife/31364.aspx
As far as spread goes it is extremely difficult to say some stands are only a few metres across others cover several hundred square meters.
How bad, well it's persistent.
Grows through tarmac.
(http://www.steger-lewis.net/aj/images/knotweed/jktarmac.jpg)
Grows through foundations & comes up indoors.
(http://www.steger-lewis.net/aj/images/knotweed/in_the_house.jpg)
Most councils do deal with knotweed and as far as I know it is a notifiable weed these days.
Thanks - have contacted the council and they told me they are well aware of the problem and spray it several times a year. Apparantly there used to be a huge forest of it!
Spray it, cut it,damage it as often as you can untill it gives up. In my garden I found the best method was to cut it off and introduce a neat weedkiller into the stem, but whether thats frowned upon I do not know. It got rid of most of it but I hit it each year to keep on top of it.
We did the same as ipt8 with a reasonable success rate, managed to scrounge a syringe from a local friendly Paramedic and injected neat Roundup into the cut off stem.
BUT - don't try and compost the cuttings, they will not rot, burn them immediately.
Here in Birmingham,it's a 'notifiable' pest weed - we successfully stopped the council taking part of the area we walk dogs/pick blackberries etc.etc. when we notified of them of it for some, oh! 3 years or so? while they barricaded off the area & dealt with it. Even then, the area, which had been earmarked for building, was then changed to be a car park....
We're not allowed bonfires, but to dispose of bags of knotweed we are supposed to NOT put it in the garden refuse sacks or black bags for landfill, but to telephone them to collect & dispose of separately...fine, if people know what it looks like....
Quotewe are supposed to NOT put it in the garden refuse sacks
How much of it ends up in the bogoff bags of compost you all insist on buying? All the recycled green waste ends up in the likes of Lydel stores.
Don't know if you've treated it yet!If not RoundupTree Stump and Rootkiller is said to be the only one to tackle the problem.good luck!