japanese knotweed

6pointer

Well-Known Member
Was walking round my area when i came across an area of about 50 sq feet fenced of like a stock dence and the sign read keep out Japanese knotweed contaminated soil do no remove so whats the problem with this stuff because the deer are eating it.
 
It will regenerate from a small piece of stem or root (only mm long) and once established is very difficult to get rid of. Excavations can be 3m deep... Alternatively you have to direct inject the stems over the course of a couple or three years. It is allelopathic (the leaf mulch supresses other plant life) and there is very little in the way of native wildlife that eats it.
The govt is currently considering the use of a biocontrol agent to rein it in.

Seriously bad news.

Regards

G

PS I have seen it grow through concrete floor slabs, tarmac and from being buried over three feet deep. This stuff and cockroaches will be left after a nuclear war :-{
 
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Sounds bad i was woundering why it had a fence round it (THAT MUST HAVE COST A FEW QUID) i will need to take a picture next time it also say dont remove any soil and the devil in me thought about lifting some just for the sake of it :lol:
 
True 6pointer - a quarter inch of that white root in amongst a barrowload of inviting soil for a rockery or border - whatever - will create mayhem in a year or two. Like Rhododendron ponticum, a legacy from times when it was 'FUN' for landowners to import interesting plants with them in order to impress and have something new..
 
hi,

the reason there is concern about this plant is two fold
one it casts thousands of seed in and around September time which enables it to spread real fast
the second which is more important is the oil/liquid it produces when broken damaged or rubbed against
it cause severe reaction to skin similar to a burn blister.
my advice is if you see it keep away from it
25 years ago i got some on my thigh and forearm i still have the scars... be warned

f.
 
hi,

the reason there is concern about this plant is two fold
one it casts thousands of seed in and around September time which enables it to spread real fast
the second which is more important is the oil/liquid it produces when broken damaged or rubbed against
it cause severe reaction to skin similar to a burn blister.
my advice is if you see it keep away from it
25 years ago i got some on my thigh and forearm i still have the scars... be warned

f.

Frank, I think you are confused between Japanese knotweed and Hog weed, Hog weed is the one that causes blisters to the skin.
Both are invasive alien species that have become established in this country.

Those of you who are in central Scotland will find both species growing on the banks of the Forth.
 
A subsidiary of the company I work for specialises in soil remediation and Japanese Knotweed is one that crops up a lot. As others have said, the stuff is nigh on impossible to kill and can cost thousands to clear up. Are you sure the deer are eating the knotweed? I was under the impression it was pretty much unpalatable save for the shoots in spring?!

Alex
 
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Ive hogweed burns from over 30 years ago....stuff smarts for sure. Knotweed is a mare. I manged to get rid of a small clump by injecting but it was a long haul
 
So if the golf coarse near me dosnt give me permmison then a spade full of soil will have them panicing lmao Any with rgards the deer yes they are in the fenced area and the woody tissue has been eaten it is also a place of good quality food ivy bramble willow buds and winter barly so the glasgow roe deer seem to like it.:eek:
 
If the patches of Japenese Knotweed aren't too big then it not really that difficult to remove. It can be sprayed with Glyphosate or Timbrel and, if you are persistant and keep checking it and spraying any new growth several times a year, you will beat it. Get to recognise the plant because you will often see new plants pop up a good way from the initial sites. The problems come when the sites are very large and already unmanageable or they are near watercourses or there is some other reason to prevent effective spraying. As has already been mentioned, it must not be strimmed or mullered with a hedge cutter as this only spreads it far and wide yet many local authorities still do this especially on roadside verges. Foliar application is as effective as injection in my experience. Do not remove the dead foliage just let it die back on site. I have got rid of knotweed on two estates but I hope my sucessors have kept an eye on it or it will be back.
 
with rgards the deer yes they are in the fenced area and the woody tissue has been eaten it is also a place of good quality food ivy bramble willow buds and winter barly so the glasgow roe deer seem to like it.:eek:

Excellent! We'll advise our clients to get more deer in! :norty:
 
If the patches of Japenese Knotweed aren't too big then it not really that difficult to remove. It can be sprayed with Glyphosate or Timbrel and, if you are persistant and keep checking it and spraying any new growth several times a year, you will beat it. Get to recognise the plant because you will often see new plants pop up a good way from the initial sites. The problems come when the sites are very large and already unmanageable or they are near watercourses or there is some other reason to prevent effective spraying. As has already been mentioned, it must not be strimmed or mullered with a hedge cutter as this only spreads it far and wide yet many local authorities still do this especially on roadside verges. Foliar application is as effective as injection in my experience. Do not remove the dead foliage just let it die back on site. I have got rid of knotweed on two estates but I hope my sucessors have kept an eye on it or it will be back.

Paraquat and oust mixed with a little petrol/diesel solution each applied at the right time works wonders
just a shame the best method of eradicating Knotweed I found is now banned in this country

but Timbrel/deisel mix followed by burning at a later stage , then a quality neat glyphosate based products applied as needed when the foliage appears in numbers will hav a desired effect
costly but worth it
 
Timbrel is expensive, £100 for 1.5 Ltrs, it is effective though.

you can mix it with Diesel about 50/50 if you want to kill everthing sprayed or painted on, but never mix it with glyphosate as they counteract each other and only one chemical will hav the desired effect
 
Is introducing petrochemicals into the soil a good idea? I mean there are plenty of chemicals that will kill knotweed (and every other living thing for that matter) but isn't the trick to remove the knotweed whilst maintaining a non-toxic and unpolluted soil?

Alex
 
you can mix it with Diesel about 50/50 if you want to kill everthing sprayed or painted on, but never mix it with glyphosate as they counteract each other and only one chemical will hav the desired effect


I use it neat on tree stumps, apply to the cambium, job done!
 
sorry Alex
should of made my post clearer
when added such parts as Diesel the spray or wipe effect is more as a direct application than as an over spray
it makes a huge difference to cost and contamination
infact if you look at it a different angle
contamination from certain petrolchemicals does no more damage to soils of a established crop than a tri yearly dose of Glyphosate/mix
after about 3-5 years the ground flora starts to renew and you would never know the difference except in the pocket
 
sorry Alex
should of made my post clearer
when added such parts as Diesel the spray or wipe effect is more as a direct application than as an over spray
it makes a huge difference to cost and contamination
infact if you look at it a different angle
contamination from certain petrolchemicals does no more damage to soils of a established crop than a tri yearly dose of Glyphosate/mix
after about 3-5 years the ground flora starts to renew and you would never know the difference except in the pocket

Fair enough. I just remember when my old man decided to clean out the fuel tank of our old camper van. There was a bald spot on the lawn for two years! :lol:
 
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