A reoccurring client has asked me to remove Japanese Knotweed from one of her properties. I told her this is a huge undertaking and that if she really wanted it gone I would need to bring in a backhoe. She’s wasn’t into it, for she is selling the property. I told her I would do what I could but no promises. My new plan is to lay down some 2ozWCF, top soil, and mulch it. Figure the roots will move from the area and as long as someone keeps the lawn mowed it should vacate. 😂🤣😂 really this is wistful thinking. Anyone have any pointers? Whoever the dink it who decided it was a good idea to line our highways with it...

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    WCF? World Curling federation, Windows communication foundation? What is it? A geotextile?
    – kevinskio
    May 22, 2019 at 12:01
  • Poly-woven weed control fabric. May 26, 2019 at 9:50

2 Answers 2


The answer depends on the legislation in your country.

For example in the UK, it is not illegal to have knotweed in your garden, but it is illegal not to control its possible spreading into adjacent properties. If such spreading does occur it can be subject to a criminal prosecution under an amendment to the Anti-social Behaviour, Crime and Policing Act 2014.

Garden waste containing knotweed is classed as 'controlled waste' under the Environmental Protection Act 1990, which requires disposal at licensed landfill sites, and transportation by a registered waste carrier.

If you sell a property in the UK, you are required to make a statement whether or not knotweed is present, and if it is present you are required to state what is the management plan by a professional eradication company to remove it, and whether that plan has a transferrable guarantee. These declarations are required by mortgage lenders.

The idea that you might contain it by weed control fabric and regularly mowing the lawn could be politely described as "fanciful."

  • I am awfully fancy. 😉 We do not have such legislation in the United States yet. When I read the Umaine website on control in our area it tells me that if I keep the stalks cut down that this will disrupt its growing cycle. This is why I thought to just block out the sun. Also, it talked about using glyphosate on exposed parts of the plant but I also try to avoid using poisons. It seems that removal companies in the UK use heavy mechanical equipment. I don’t feel good about this. It’s too close to the house and I would have to take out most of the yard. Seems like an uphill battle. Thank you. May 22, 2019 at 11:37
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    @Aonewilkenson: if its close to the house, you really need to do something about it - Japanese knotweed will punch up through concrete and your floors, which is why mortgage companies in the UK want to know its being dealt with. There are some mortgage providers who will not provide one if this plant is within 30 metres of the property, and insurers won't insure the building either. Roots go down to about 9 feet - not sure that constantly cutting it might not just mean the roots spread further out (and closer to your house)...
    – Bamboo
    May 22, 2019 at 21:52
  • @Bamboo thank you for the heads up! There is a bit near the house but it’s not too much. I don’t like to dig it up cause it’s so easy to miss and kinda spreads it. I have also heard of people using glyphosate. I however would like to avoid using poisons if possible. May 26, 2019 at 9:49
  • The usual 'home' method of trying to contain/kill it is to cut down the stems (they are hollow inside) and drip round up or glyphosate inside them. Over time it does deter and kill some of it, but it needs to be repeated regularly over years. There are times when poisons are necessary, and as this isn't being sprayed, its just dripped neat inside the stems, its less damaging to the environment generally.
    – Bamboo
    May 26, 2019 at 10:56

You can eat it if you want an interesting treat: https://www.youtube.com/watch?v=3QzMNKAQo9Y

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    I have been harvesting the roots, for it’s said to be a great help in the fight against Lyme Disease. May 22, 2019 at 11:15

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