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Japanese knotweed

22 replies

misdee · 04/10/2013 23:13

A gardener friend of mine spotted it in my front garden today. I am not a gardener, and truly suck at it. I can just about cope with mowing the lawn.

Anyway, I have contacted the LA landlord about it, and been googling about how to get rid of it.

Is it really going to take 3-5years to eradicate it? I was planning on re doing the fences and fake turfing the gardens next year (i say gardens, the back garden is more of a yard, its tiny). Is this now not going to be possible because of this plant? Will the LA landlord take care of disposing of it, or will it be down to us?

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misdee · 05/10/2013 11:03

anyone?

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cantspel · 05/10/2013 21:20

I have never had to deal with JK but i do know someone who had a battle which lasted a couple of years with it.

It is not worth trying to dig it out as any little bit of root will regrow. You need to treat it with glyphosate but i wouldn't start until next year on the fresh growth as it will be being to die back now but come next may it will be about a metre high again and ready for its first treatment. Then take the tops off the stems and inject the glyphosate straight into it. The plant as it grows will then carry the chemicals down to the root to start killing it, treat again at the height of the summer and again at the end.

You will probably have fresh growth the next year but the stems should be weaker and probably look warped and damaged. Treat again the same as year 1 and keep treating any year you see any fresh growth. It will die eventually but you have to keep at it.

Be careful if digging around it as it is very easy to spread any little bit of root will turn into a fresh plant. Destroy any bits of it you have cut off by burning and make sure none gets put in your compost as it will regrow.

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misdee · 05/10/2013 21:51

thank you.

I will put off re-doing the front garden until this plant is gone.

I am shocked at how quickly it grows

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Rhubarbgarden · 06/10/2013 08:19

I got rid of JK by glyphosating weekly for six weeks. That dealt with it.

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moonbells · 06/10/2013 08:22

Read this article. Helpful and has links on how to get shot of it and also contact info for a firm which guarantees removal.

Not cheap though!

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Blackpuddingbertha · 06/10/2013 11:44

As you're renting I think you need to get the landlord to help pay for getting rid of it. It won't be cheap, or quick, and can do horrendous things to buildings too so it's definitely not just your problem. Good luck.

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misdee · 06/10/2013 17:04

It's local authority/social housing. I just want it gone.

Spotted it in my neighbours garden as well and she is a different HA, so will have to let them know as well.

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purplewithred · 06/10/2013 17:20

it's a tough devil but you can keep it down. Is it an isolated patch or is it creeping in from next door? If it's an isolated patch I would dig it out (deep down and under it), put it in the bin in a black bag, grass over the spot, then when it inevitably resprouts again next year mow it and keep mowing it and never let it get any taller than the grass. At least it's under some control. Every so often I'd give it a blast of post-mowing glyphosate too in case it's not getting the message.

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denialandpanic · 06/10/2013 17:27

fyi it's an offence under the wildlife and countryside act to allow it to spread or to dispose of it incorrectly (ie. put it in a black bag in your bin). op the local authority as your landlord will deal with it.you need to ring whoever handles the grass cutting /verges contract or try environmental health (they won't deal with it but might know which section will)

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misdee · 06/10/2013 21:15

I wasn't going to black bag it.

I did trim it back last year and just bung the ends in the council bin, but that was before I knew what it was.

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cantspel · 06/10/2013 23:35

The problem is you cant force your landlord local authority or not to deal with it as it is only illegal to knowing plant or spread it but there is no law that says you have to treat it when it is growing on your land. So i would just deal with it myself as you can treat it quite cheaply with a glyphosate based weed killer. You can buy kurtail on ebay which would work better than anything you can buy over the counter in a garden centre. I would not try digging it out unless it is a very small area as Jk has an extensive rhizome root system which will break up and spread very easily so where you have one plant now you could find you have 10 plants to deal with next year.

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echt · 07/10/2013 08:03

Go to the eattheinvaders website for recipes using JK: JK vodka, JK wine, JK muffins.

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PossessedPollyPumpkin · 08/10/2013 19:47

Was just about to start a new thread about this.
There was something about it on the one show the other night.
I don't usually watch it Blush honest I don't, but I am glad I did this time. I hadn't heard of it before.
I think I might have a bush in my garden, but not too sure.
Got a pic on my profile. If someone could confirm that would be brilliant.
It hasn't really spread much over the 5 years we have been in the house. We cut it back as needed but no more than other bushes in the garden.
We had a survey done before moving in but nothing was mentioned.

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PossessedPollyPumpkin · 08/10/2013 19:53

I have goggled images, my bush does look similar to a lot of them - just with out the white flowers.
Tbh most shrubby type bushes look the same to me, so don't know if I am worried about nothing.

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misdee · 08/10/2013 19:58

are the stems hollow?

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ghostonthecanvas · 08/10/2013 20:01

If you have pink flowers it could be himalayan balsam. It is similar. Grows really fast. Its not as invasive as JK. Has a funny way of popping its seeds. If you touch the pods they burst open.
Council obliged to deal with JK in our area.

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PossessedPollyPumpkin · 08/10/2013 20:02

Notches stems aren't hollow. No flowers at all. It was the red stems that made me think it could be JK.

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OhOneOhTwoOhThree · 08/10/2013 20:09

Where are you ghost? I'm about to start on an expensive course of treatment for JKW (on the advice of my letting agent).

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ghostonthecanvas · 08/10/2013 22:36

Highlands OhOne. It is worth finding out from your council. Awful stuff JK

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OhOneOhTwoOhThree · 09/10/2013 00:38

Thanks ghost.

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JustinBsMum · 09/10/2013 00:52

I had it in my garden when I moved in. Spray it with glyphosate following the instructions, it might need a second spray later in the year. Then watch out for new shoots or seedlings (mine had spread seeds) and spray them. It's been 10 years but I still get the occasional new growth but I would say that that is from seeds. Once you know how to recognise it just spray when it appears. No big deal imo, just make sure it doesn't flower and spread seeds.

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mermaidbutmytailfelloff · 09/10/2013 02:21

BBC Inside out on 7 October (London) had a piece on knotweed. It should be available on Iplayer although I am outside the UK so can't check. Apparently interesting, about how scientists can control the spread.

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