Panic! Panic! Japanese Knotweed!

[Adam Cheeseman]

Originally Posted by Jim Ford

The plant absorbs the glyphosate and it will eventually kill the whole planet - roots and all.

I know it's invasive, but ye Gods.

Seriously though, multiple applications of Glyphosate will be needed. Over how long will depend on how long it has been established.

Cheers,

Adam

[nigel_b]

Originally Posted by Jim Ford

Glyphosate (Monsanto 'Roundup') .... <cut>.. will eventually kill the whole planet ...



Jim

Unfortunate typo Jim!

Don't hoe it.

Glyphosate it.

Don't be digging it up, ripping up the decking, etc, just spray it gently with....glyphosate, light up the barbie and put your feet up.

Glyphosate, make it work for you. It'll kill anything green it touches, eventually. You might need two or more goes but let it do the work. In some sensitive places they have "weed-wiping" sessions as described above.

I honestly think if you go digging it and hoeing it you'll actually make the problem worse.

[tingers]

Wow, guys thanks so much for all your comments so far! Jim Ford's comment about Glyphosate eventually killing the whole planet was a hilarious typo but basically sums up my impression of using weedkillers!

Another one of my friends came round yesterday and, after all this panicking said it might be just bindweed. So far, I'm not letting any of the green bits get big enough to really see what they look like when fully grown, but I took a photo of the roots I pulled out.



Is it just bindweed?

I've got a tree surgeon friend coming round soon to have a proper look, but he's busy for a while and it'd put my mind at rest if you could tell by looking at it.

Cotham Marble thank you for acknowledging my decking and gravel needs! I think you're right about the previous owner of the house: he took shortcuts indoors so I wouldn't be surprised if that slapdash attitude prevailed in the garden too!

[Stinky Bob]

I am no expert but those roots look a bit thick for bindweed

[Jim Ford]

Originally Posted by tingers

Is it just bindweed?

It's bindweed.

Part of my garden was overgrown with it and I recently dug it all up and filled 2 green 'wheeliebins' with the roots. They're about the thickness of spaghetti.

No doubt I've left fragments of roots behind, but if they grow glyphosate will take care of them.

Jim

[Cotham Marble]

Originally Posted by tingers

Wow, guys thanks so much for all your comments so far! Jim Ford's comment about Glyphosate eventually killing the whole planet was a hilarious typo but basically sums up my impression of using weedkillers!

Another one of my friends came round yesterday and, after all this panicking said it might be just bindweed. So far, I'm not letting any of the green bits get big enough to really see what they look like when fully grown, but I took a photo of the roots I pulled out. Is it just bindweed? I've got a tree surgeon friend coming round soon to have a proper look, but he's busy for a while and it'd put my mind at rest if you could tell by looking at it.

I agree with Jim, that looks very much like bindweed. Just to be certain though, grow on a few sections of root in a pot, it'll leaf up within a couple of weeks and you'll be able to certainly identify it yourself - there's plenty of images of bindweed and JK on the Web and you can't easily confuse the two.

Bindweed can be a problem and it's worth digging out all you can from the beds you have created. The membrane will suppress the bindweed from breaking through - but the roots are likely to survive for a number of years and you'll probably have promblems all around the edges of the membrane. I've dug out bindweed roots from a metre and half below the top soil, so be prepared for a long fight. Using glyphosate based 'paint on' preparation for the points where it does break through is probably a reasonable compromise to keep the bindweed from getting heavily infested on the membrane edges.

CM

[Jim Ford]

I didn't find it too bad to dig up.

The roots were only a foot or so and using a fork the tangles of roots were easily brought to the surface. The worst part was constantly bending down to pick them up! Don't use a spade, though.

Jim

[tingers]

So far, I've been digging up roots from the beds I've dug out - there are so many of them and they're so very very long. The hardest thing is trying not to snap them and actually trying to get the whole length of root out, because they seem to be up to 2 or 3 metres long. And a lot of the roots seem to come from beneath the gravel so sometimes they just won't come out. I know that these are likely to grow back... :-/

Cotham Marble - you're right. Where there are seams in the membrane, the weed grows up. For now, I'm going to just weed them out and try to cover the gaps. I'm really not keen on using chemicals. But I suppose if that doesn't have much of an effect, I can get some glyphosate paint - on stuff. So, do I literally just apply it to the green parts of the plant that come through, and will it kill the roots?

[Jim Ford]

Originally Posted by tingers

I can get some glyphosate paint - on stuff. So, do I literally just apply it to the green parts of the plant that come through, and will it kill the roots?

You can get a ready to use spray of about a litre of ready to use glyphosate for about £8 (IIRC). The chemical is absorbed by the green parts of the plant and kills the whole plant, including the roots. As the leaves appear above ground, just go round giving them a squirt. The spray can usually be adjusted to give just a local application. You need to do it during a dry spell to give the plant time to absorb the chemical. After a couple of days or so you'll see the new growth of the plant coming through yellow, which is quite satisfying.

Jim

[Cotham Marble]

Originally Posted by tingers

But I suppose if that doesn't have much of an effect, I can get some glyphosate paint - on stuff. So, do I literally just apply it to the green parts of the plant that come through, and will it kill the roots?

Actually I might have given you a bum steer reaint on herbicide. It's been years since I used any and it seems that these type of products have been withdrawn. The hand sprays (like kitchen cleaner bottles) seem to be the closest thing available now. Glyphosate (there are various commercial preparations) is a systemic herbicide which the plant absorbs on contact and the chemical then moves throughout the plant causing damage. Bindweed is pretty tough so although one application of glyphosate will kill off the above ground parts, some roots will remain to send up new stems and a second application will be required. I share your reluctance to use chemical controls but my guess is you have masses of roots below the membrane and in that particular circumstance other forms of control are going to be very difficult to put in place.

CM