Japanese Knotweed...... Anyone Hungry?!

[RobRainford]

fly tipping of the material seems to be a big spreader of the plant. Plus it really does take nothing to make it grow.

 

theres a pub near me with a farmers field at the back full of it at the edge. You would think its a hedge theres that much!

[the villan]

anyone know a way of getting rid of the stuff,been trying for years,

[Green man 1970]

anyone know a way of getting rid of the stuff,been trying for years,

 

I've only been asked to remove it a few times in the past and I've cut the stems off with secateurs to prevent debris being spread, then filled each stem with Round-Up. Don't forget to burn all the waste! This will work on small patches of it, but I don't know about the wholesale removal of the stuff. I'm sure there are plenty of people on here who have plenty of experience of this!

[Dowie]

I see quite a bit round my area west sussex, in hedge rows, even outside the council tip! I do some maintenance at place that has quite a heavy infestation. In the past I think someone has used something pretty strong on it, and it is affecting some of the mature holly trees in the immediate area and some of the laurels as well. But the knot weed still comes back year after year. Given that there is something that has stayed in the soil for sometime I don't think I will be trying that recipe:biggrin:

[RobRainford]

I've only been asked to remove it a few times in the past and I've cut the stems off with secateurs to prevent debris being spread, then filled each stem with Round-Up. Don't forget to burn all the waste! This will work on small patches of it, but I don't know about the wholesale removal of the stuff. I'm sure there are plenty of people on here who have plenty of experience of this!

 

You shouldn't be cutting it. It's classed as propagating it. You could miss that one little piece and grow a whole new plant! You are best spraying it with a high concentration solution late summer/ autumn when it starts to pull it's reserves back in to the roots. If you get it right and hit it hard you can achieve a good level of control. We were getting 90% control using this method. We now stem inject where possible. This can be done any time of the growing season. And we were seeing upwards of 95% control.

 

We have just done a garden full of it. Garden probably wasn't more than 10x13m but we had to remove 15 ton of soil. Then put 15 ton of clean soil back in! The roots had spread 2 gardens each way. One bit has gone through the foundations of the house, another is coming up though a garden shed. Inside it!

 

The most severe is where it's grown under the house then gone up though the cavity wall. To remove that the whole outer wall has to come off!

[richy_B]

I treated about 5 hectares of knotweed last season in West London. All the Thames tributaries and the overground system have it growing in abundance. It only now seems to be getting to a point of real concern and I've seen mention of it on building insurances (similar to the proximity of large trees). The potential for damage is significant in my opinion.

[RobRainford]

I treated about 5 hectares of knotweed last season in West London. All the Thames tributaries and the overground system have it growing in abundance. It only now seems to be getting to a point of real concern and I've seen mention of it on building insurances (similar to the proximity of large trees). The potential for damage is significant in my opinion.

 

 

it has a very high potential for damage and costly damage too. I dare say, moreso than large trees and their roots.

[VEG]

I have seen knotweed grow through concrete, it is severely damaging and will grow through almost anything.

[richy_B]

A photo I took last season. There could be some some structural movement involved here as well but I'm confident the knotweed is a strong contributor (a large amounts of the stems have been washed away during high water levels) The worrying thing is this was a support for a two lane road bridge.

 

[RobRainford]

The worrying thing is this was a support for a two lane road bridge.

 

 

that's frightening.

 

Its a tough one to say over a pic. But I would say that's some other factor causing that major damage and JK has just entered and made it a bit worse.