Japanese knot weed

[colwoodlandcare]

I've had some one enquire about putting in a root barrier to stop the spread of Japanese knot weed. What sort of depth should I be going to? 2m.

Also where is a good place to purchase root barriers.

[slack ma girdle]

I've had some one enquire about putting in a root barrier to stop the spread of Japanese knot weed. What sort of depth should I be going to? 2m.

Also where is a good place to purchase root barriers.

 

You will need to go down about 6m, and that a lot of digging. the only way to stop it spreading is to treat it with chemicals.

[treesrus]

You will need to go down about 6m, and that a lot of digging. the only way to stop it spreading is to treat it with chemicals.

 

agree with that, i,ve been dealing with an area that was bull-dozed in the 60's, burying knotweed to various depths. the stuff keeps showing up in different places. the only way to be sure is to dig it up all the roots and incinerate, although persistent applications of Glyphosate works quite well.

[colwoodlandcare]

That could be a bit of an issue. The clients neighbour has the knot weed but isn't bothered by it. My client wants to stop the spread into his garden without paying out to get rid of it from the neighbours.

Would you say a 2-3m deep root barrier wouldn't stop it.

 

 

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[treesrus]

depends on how long it's been there and how large an area it covers will give you an idea of how deep the roots are. start of with a bi-annual treatment of glyphosate (stem injection and spray), might just do the trick.

[peatff]

Wait till it gets to your friend's property then contact the owner of the infected land and tell them you are going to take legal proceedings.

 

Third party litigation – Landowners can be sued for costs and damages if they fail

to prevent knotweed from spreading to a neighbouring property. Also failure to

manage and dispose of Japanese knotweed responsibly may lead to

prosecution.

[growforest]

I understood it's a notifiable weed, so landowner should do something about it. Root barrier wont stop a few seeds popping over the fence, and will need to be very deep if plant is established. Quickest route may be to get go-ahead to spray, spray, spray.

[Keithrturner]

If it's spread from the neighbours property, then legal action is possible, if you have it on your property you are not required to do anything about it, but you must prevent it spreading to neighbouring properties, or incur legal action.

 

JKW does not spread by seed in the UK, it spreads by roots and green material (stems, leaves).

 

Standard spec for excavation would be to 3m depth (with inspection for deeper roots) so I would say that any membrane needs to be at least 3m deep too.

[renewablejohn]

You will need to go down about 6m, and that a lot of digging. the only way to stop it spreading is to treat it with chemicals.

 

You can kill it with steam injection under a plastic cover.

[peatff]

Root barrier wont stop a few seeds popping over the fence, and will need to be very deep if plant is established. Quickest route may be to get go-ahead to spray, spray, spray.

 

It doesn't spread by seeds it is purely vegetative reproduction by sections of rhizome. RHS site describes it here. I have some growing over the wall from me on land belonging to the local Chinese and they are not really interested in it so when it gets close I go over and chop it down but this year I got some Rosate glyphosate from the local allotment and am trying spraying at 20% and injecting neat into the stems of the nearest ones. It seems to weaken them within days.