Japanese Knot Weed (Merged)

Davesnave

Lots of pictures here:
http://www.devon.gov.uk/index/environment/natural_environment/biodiversity/japanese_knotweed/knotweed_in_devon.htm

There are ways to get rid of knotweed; maybe not cheap ways, but you don't have to employ a specialist. Knotweed will eventually succumb to treatment with glyphosate, but not in one season and not if you forget to keep up the treatment - hence Knotweed! The problem is that many people expect instant solutions, and this leads to the development of a mythology that is almost as hard to eradicate as the weed itself.

Of course cost and difficulty of control are determined by the scale of the problem, but not many gardeners have half an acre of railway embankment or riverside of the stuff to manage.

MoJo

Lotus-eater

Pretty normal looking isn't it?
Any way to really notice it easily?

arkonite_babe

mrsorganised wrote: »

Did you know that the rate this weed is growing it will eventually take over by strangling our natural habitats e.g foxglove etc., our beautiful woodlands will disappear for ever! It is vertually impossible to get all the root up,so the best thing to do is if you see it in flower is, DEADHEAD IT SO THE SEEDS DONT SPREAD!

We have a thread similar to this already, I've added your query to it so all the replies are together. Posts are listed in date order so you'll need to read from the beginning to catch up

Wig

I noticed a farmer near me had a 6 metre section of his hedge which had become all 100% knotweed, he sprayed it with something 2 years ago, It died off and went brown over that summer, last year I noticed a huge 6 meter gap in his hedge with no obvious grow back, this year the gap is still there and I think there is a little bit of grow back, I suspect he is going to treat it again. Whatever he treated it with certainly had a big effect on it.

Now I suspect the OP is referring to expensive weedkillers such as glyphosate "roundup". It is very expensive and I found the cheapest way to buy it was in concentrated form, called something like "Roundup Ultra 3000" 3000 refers to the 3000 sq meters that the bottle will treat. Years ago this 1 litre bottle in the UK cost £40 :eek:

But I found the exact same thing (different brandname) on sale in a French DIY shop for £10, the Branded stuff (roundup) in France was twice the price @ £20 still half the price of the UK!

So, if you or anyone you know are visiting France, tell them to vist a DIY megastore and get a litre of glyphosate concentrate 360 g/l (360 grams per litre). The one I got is called
Univers Jardin - Glyphosate 360 g/l & comes in a yellow box.

Some of the huge hypermarkets also stock it in brandname roundup ultra - 3000m" form for about £20 one to try would be E Leclerc

And RoundUp GT plus is a new more concentrated version with 400g/l and as you can see it might be found on Ebay from time to time
http://cgi.ebay.com.sg/DESHERBANT-ROUNDUP-GT-PLUS-900ml_W0QQitemZ360029280200QQihZ023QQcategoryZ519QQcmdZViewItem

elsien

Lotus-eater wrote: »

Pretty normal looking isn't it?
Any way to really notice it easily?

Yes - the speed it grows at - ends up taller than me apparently overnight.:eek:
(Slight exaggeration maybe, but not far off.)

Wig

Lotus-eater wrote: »

Pretty normal looking isn't it?
Any way to really notice it easily?

You can notice it easily because especially at this time of year it looks like a clump of dead bamboo. It dies off over winter and the stems are hollow, they dry out and become brittle/brown.

If you see a large clump of hollow stems, in an urban environment it is likely going to be knotweed, later on in the summer you will see the dead brown stems in amongst the green ones and you can confirm the identity by looking at the leaves which are big and flat about 10 - 15 cm across

RAS

We found that cutting the canes in August and injecting them with Glysophate worked very well, as the herbicide is drawn back down into the roots as it dies back. The National Trust do this with very high concentrates of glysophate (10 times the recommended dosage).

For re-growth we painted the leaves rather than spraying to avoid drift and slashes.

arkonite_babe

For anyone still having knotweed problems, get your own back and eat it!!!

http://www.wildmanstevebrill.com/Plants.Folder/Knotweed.html

Jack's_mummy

I was just about to post that too - I saw a recipe in last months countryfile magazine and couldn't believe it. Not sure I'll be trying it though