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Japanese knotweed

Our new garden has the dreaded weed. I'm planning on injecting it with glyphosate. I know it's best to wait until early autumn but I'm worried that by then we will be over run. Would you start tackling it now or wait and watch it march onwards for another 2 months?



  • sotongeoffsotongeoff Posts: 9,802

    I have never experienced this but am aware of pouring glyphosate into cut stems- at this time of year whilst it is actively growing I would repeatedly spray the leaves every 2/3 weeks with a glyphosate spray- at least that will weaken it and stop its progress

  • BenDoverBenDover Posts: 480
    Japanese knotweed is hollow. Best way of getting the weed killer into,the plant is to cut the stem, leaving about a foot off the ground and then syringe the solution into the hollow. Once you beleive the plant is dead, It is advisable to dig up and take away the soil, as the rhizomes could still be lurking in the ground and the plant could regrow. If you cant take the soil away, then you need to dig over the ground, which may cause new growth from chopped up rhizomes, but they can be treated with weed killer eaiser. It can take several years to be sure to be rid of it completly.

    For disposal, you need to contact your local authority who can tell you where to take it. Not all local authority sites will take it. You can burn it, but that can lead to other issues (ie, nuisance and/or pollution).

    If the plant is only on your land you could end up causing a private nuisance if you allow it to grow on another property. It must therefore be controlled and preferably eradicated. Conversely, if you have it encroaching on you land from a neighbour, you need to work amicably together to get rid of it.

    The plant is covered by the Wildlife and Countryside Act making it an offence to let it grow in the wild - this includes disposing of it which could result in it taking root in the open environment.

    Japanese Knotweed can reduce the value of your house - I know one person who had his house value knocked down by ??10K when he was trying to sell it and during the survey it was discovered he had it in his garden (there from a previous owner). When he set about removing it, it was discovered to be invading local authority land, who subsequently told him to remove it and the soil costing ??7K. He then had to indemnify the new property owner against the knotweed from returning for up to 5 years.

    I watched a TV programme once where somebody harvested knotweed and served it up as dish -she said it tasted like asparagus!

    Good luck!
  • yes, eat it, bit like rhubarb. i went on a foraging course and learnt you can have it raw, like in a salad, cooked, whatever basically and it's very good for you.  so don't kill it. EAT IT!

  • cloud8cloud8 Posts: 103

    There was an enormous specimen of japonese knotweed when I moved into my last house - no one told me what it was or that I could get money of the house, never mind.  The previous owner grew it because he thought it was pretty.  It lurked next to the front door like a triffid and my friend with a horticulture degree identified it as an orchid.  Once I found out what it really was I used Roundup.  Then I dug up regrowth and burnt it.  Eventually it rarely came up at all and if it did I gave it a blast with a flame gun which was quite good fun and seemed to do the trick.  It does weaken eventually.  I wish I had know I could have eaten it.  I'm sure I read that Alys Fowler eats bindweed, can anyone confirm this?

  • Tropical SamTropical Sam Posts: 1,488

    You can also eat Bindweed shoots and I guess they taste like grass from the smell but there are plenty of tastier things to eat in life.




  • talking of tasty things to eat, on my foraging course we ate Lime tree blossom which was seriously wonderful. you can also eat the raw leaves from that daft plant that as kids you chuck at people and it sticks to them (it has little bobbles on it as well?). Ha, ha cloud8!  I like the image of you blasting the lurking triffid and then your learned friend saying it was an orchid! 

  • Make sure before you eat it that someone hasn't treated it with glyphosate!!!!

  • damn right! excellent point, gardeninggenes. 

  • Tim Burr

    I'm sure you've covered every aspect of knot weed destruction, but I have heard that you should break the membrane that occurs at the joints so you can get more glyphosate in and also so it will get closer to the roots.

  • LizWLizW Posts: 1

    Can anyone tell who I would need to contact about Knotweed that is growing along side the road in several places in my area?

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