evil bloody plants (Japanese Knotweed)

Mirandola

The pretty plant down the road turns out to be japanese knotweed. I hear this is bad. Anyone out there got any experience of dealing with Islington Council on this?

tosscat

Wots is you can eat it.

Mirandola

I was thinking something more radical and less nibbly. Maybe some really peckish rabbits?

taff bach

Japanese Knot weed is vile. It puts out toxins and kills everything around it. It took me 5, yes 5 years to get rid of it. It managed to go 15 feet under concrete to the next garden and can push up through foundations. Its roots go at least 8 feet deep. Cut it down and never let it grow to more than 2 inches, generously feed it with industrial strength Roundup or similar systemic weed killer and learn to hate with a vengance.Vast swathes of Wales have been blighted by this invader, Good luck!

taff bach

p.s. If your bunnies have been snacking on this shit do not eat the corpses!

Mirandola

Thanks Taff Bach. The bunnies were a figment of my imagination, fortunately.

The problem (well, the extra problem) is that the wretched plant is not in my garden.

So I can't just go in and attack it.

N4mality

Wikipedia has a good write up on it

http://en.wikipedia.org/wiki/Japanese_knotweed

"The most effective spraying solution contains about 5%-10% glyphosate in water. (To make a 5% solution from a 40% concentrate mix 1 part concentrate with 7 parts water.) Ready-to-use solutions that contain less than 5% glyphosate are too weak and do not work. A small amount of liquid dish-washing detergent can be added to improve wetting of the leaves. If possible, both sides of the leaves should be sprayed until they are completely wet. It takes about 3 weeks for most of the plants to die. After 3 weeks, all remaining plants should be sprayed again. This process needs to be repeated until all the plants die."

Ali

You need to inject the weed killer into its stems and it can atke 5 years to kill it

Mirandola

Thanks Ali and N4mality. All useful stuff.

helen

DEFRA have been testing some new parasite that can kill it dead -

"DEFRA determined that the most appropriate solution would be to release a non-native parasite of Japanese origin known as alphalara itadori at key sites where Japanese knotweed is prevalent. The parasite, or pysllid, has been known to neutralise the effect of Japanese knotweed by devouring its sap"

so I'd definitely ask the council about alphalara itadori - they could then use it on their parkland and properties inc parkland walk where it runs rampant

Mirandola

Thanks Helen. Go parasites!

yagamuffin

So what will they release to kill the rampant alphalara itador? I can see this is going to end up with us hunting Godzilla somewhere down the line!

delaware1

I have the solution and yes knotweed is a nightmare if untreated - its actually treated as toxic waste by the govt.

I had a major infestation of knotweed on council land abutting my property. I moved in not knowing what it was and got a nasty surprise. We have successfully got rid of 99% of it so dont despair. The way to eradicate it is through stem injection - have a look on the Monsanto web side for info. Its done in July/August time and becuse the plant is herbacious it sucks the poison into the rhizomes (i.e. its root system). DO NOT cut it, touch it, strim it as you will make it worse - the stronger the plants the easier they are to kill so bizarrely you should make every effort to protect them so that they have big fat tems in late Summer. As for the council, you may have to educate them on the issue. Haringey parks dept have a firm they use regularly and who sorted my problem out. The eradiocation process takes 3 seasons but in yrs 2 and three they are simply tackling the stragglers. Get Nils Battye's number off either Haringey or Southwark councils - he is very good and reliable and s the private copntractor they use. If you end up paying its going to cost you a few hundred quid but worth every penny as this stuff gropws through concrete and if it gets into your house you'll be in a pickle. hope that helps

delaware1

by the way spraying wont work (unless done by an expert at exactly the right time) and the cpouncil may not permit it as damages other plant and wildlife. Stem injection is aceptable as it simply affect the knotweed root netowrk and breaks down in the soil.

Mirandola

Thanks Delaware1. That's very good to know and hugely useful.

Ann

Ali

Being trying to do something about the Japanese Knotweed in the Planters at the Junction of Albert and Victoria Roads. When I contacted Haringey Council I got the following response: ------- Thank you for emailing Customer Services. I regret to inform you that Japanese Knotweed does not fall under the Environment Agency's remit and is not currently the sole responsibility of any statutory organisation. Responsibility for dealing with invasive weeds lies with individual landowners who have a responsibility to control any invasive weeds, although they are not legally obliged to remove them since the natural growth and spread of these plants is not an illegal activity. However, you could try getting in contact with the following agencies who deal with the disposal of Japanese Knotweed. Netregs - Control & Disposal of Japanese Knotweed http://www.environment-agency.gov.uk/netregs/63095.aspx Japanese Knotweed Alliance http://www.cabi.org/japaneseknotweedalliance/ ---- Interestingly enough the environmental web site says under it’s legal section: If you have Japanese knotweed, giant hogweed or Himalayan balsam on land that you own or occupy you: must not allow Japanese knotweed or giant hogweed to spread onto adjacent land; the owner of that land could take legal action against you. So by not dealing with it the Council is liable to possible legal action. It will be interesting tio see what response I get to that as it would be good if they dealt with it as it spreads like wildfire and is difficult to get rid off.

Ali

Don't know why the bold large bit appeared !

Mirandola

Thank you to everyone and especially Delaware1. Turns out that the right weedkiller (roundup root and tree stump) and a little patience is enough to kill the bastard thing.

harpistic

Congrats on getting rid of your triffids - let's hope that they never ever ever ever ever come back!

Cookie

Have had this plant in my garden now for a couple of years. I have tried injecting the stems with weedkiller, I swear I heard them laugh!
It didn't work.

harpistic

It does work, it just takes a hell of a lot of persistence & carefulness. You've got to use hardcore weedkiller (Roundup), and make sure you remove every last piece of the evil monsters. As it's getting late in the year, you'll have to resume next year.

They even have tree rings, some of them!!

Cookie

@ harpistic, thanks for the advice, Roundup it is then.
Despite the fact that this plant is a complete and utter menace, it is quite lovely in appearance. Rather like Muntjacs.

harpistic

@Cookie - Bah, those triffids are too damn evil to be pretty! ;) Then again, I did do battle with them for 3 or 4 years....

Silly me, it's not too late to spray the hell out of them. Roundup is intended to be sprayed on the leaves, as it will get absorbed by the plant and destroy it.

If they're pretty tall, it might be better to chop them down to stumps a foot or so high, and spray away, as the most important thing is for the roots to die.

Once plant death has been achieved, you'll need to dig up every last piece of the root system, as they can regenerate from even tiny little pieces (as I said, evil). Even if you don't get it all this year, though, they'll be more manageable next year. But be warned that Roundup is very very very toxic.

This'll help: http://landscaping.about.com/cs/weedsdiseases/a/knotweed_3.htm

taff bach

Inject the weed killer into the stem itself, works better.

harpistic

Chopping any part of the plant increases its defences and makes it even more resilient - best to avoid chopping if you can.

Cookie

@ harpistic, would really, really, love to spray them these Triffids, but not an option as there is so much wildlife in the garden. Have had a family of hedgehogs that would trundle down the garden at night. The babies were like large nailbrushes. Could not bear the thought that via the food chain, I had killed them off.
Oh bugger, what do I do now? In the words of Homer Simpson, Damn You!!!

harpistic

How are the triffids spread out in your garden? Are they in their own area, or do they pretty much take over the whole thing?

You could get animal repellent and surround the triffid zone with them, to prevent hedgehogs etc from straying in the area?

delaware

Harpisitc I would be very wary of doing what you suggest. Firstly anything you dig out is toxic waste under statute and has to be professionally disposed of. Secondly the plant does not have roots it has rhyzomes (sic.) and you cant dig them out unless you go very deep the rhyzomes can extend to 100 ft. A small fragment of rhyzome if alive can start a new colony. The best way to get rid of them is stem injection but this will only work well in August/sept - the plants are herbacious so when they die down they suck the glysphate into their rhyzomes. I would use a professional firm as they have the correct stem injection equipment. As I say above check out the monsanto website.

Arkady

(Never mind)

harpistic

@delaware Knotweed was completely gone after 2 years. But I also dug out milk crates, a bathtub, a birdhouse, hair pins and various other junk in that time too.....

I knew what I was doing ;)

twinspark

How about burning it out does that work? Neighbouring garden has it, still at relatively low levels, house owned by London & Quadrant housing assoc. and tenant does not use garden.