Calling for a garden weed expert
Thread Starter
Join Date: Feb 2006
Location: UK
Posts: 582
Calling for a garden weed expert
What on earth is this invasive and unwanted pest, please, and how can I kill it without digging it out? Garden location is UK West Midlands.


Before I laid the slate chippings you can see in the photographs I took care to remove all visible weeds, kill (or so I thought) any that remained in germinating form, and then lay a tight mesh weed clover. This wretched thing just punches straight through it.
TVM,
XV


Before I laid the slate chippings you can see in the photographs I took care to remove all visible weeds, kill (or so I thought) any that remained in germinating form, and then lay a tight mesh weed clover. This wretched thing just punches straight through it.
TVM,
XV
Join Date: Jan 2001
Location: The Burrow, N53:48:02 W1:48:57, The Tin Tent - EGBS, EGBO
Posts: 2,298
It's Horsetail, a very ancient plant from the time of the dinosaurs. A flamethrower applied at regular intervals should keep it in check. Further advice here.
Thread Starter
Join Date: Feb 2006
Location: UK
Posts: 582
Thank you
Thank you DX.
An impressively fast and helpful response.
As I don't want to dig up the garden (not laze but more practical reasons) it seems that I will have to:
Cheers,
XV
An impressively fast and helpful response.
As I don't want to dig up the garden (not laze but more practical reasons) it seems that I will have to:
- Cover my newly laid grass with polythene sheet
- Remove all the slate chippings on to the sheet
- Lift the weed barrier sheet
- Remove all visible evidence of Horsetail
- Spray the ground thoroughly with glyphosate herbicide
- Replace the weed barrier with several layers of strong black (no light) polythene sheet
- Re-lay the slate chippings
- Stand by with a flame thrower!
Cheers,
XV
Guest
Join Date: May 2008
Location: Somewhere between E17487 and F75775
Age: 77
Posts: 723
All of which raises the question: define a weed.
One man's weed is another man's beautiful plant.
Perhaps definitions could be: something you don't want growing there...... something that comes back no matter what you do to it........something that thrives healthily on no earth and little water when everything around it is dying out......
One man's weed is another man's beautiful plant.
Perhaps definitions could be: something you don't want growing there...... something that comes back no matter what you do to it........something that thrives healthily on no earth and little water when everything around it is dying out......
More bang for your buck
Join Date: Nov 2005
Location: land of the clanger
Age: 78
Posts: 3,513
Spray the ground thoroughly with glyphosate herbicide
Join Date: Aug 2009
Location: Aberdeenshire
Posts: 10
XV105 – . Sorry to add to your problems but, between 7 and 8 you need to add something like “Spores from the pesky stuff will blow between the slates, germinate in the damp conditions and start to go again and again !!!
As for underlay sheeting I’ve found “terram” to be quite good. You can get smaller rolls that that mentioned in this site Greenseal Pond Liners & Green Roofs
“...The leaves have a waxy coat and this is what makes them difficult to eradicate. However, glyphosate weed killer will eventually kill the plant after several applications. Anything with Ammonium Sulphamate would do the trick as well.....”
It's a real b#####d !!!

As for underlay sheeting I’ve found “terram” to be quite good. You can get smaller rolls that that mentioned in this site Greenseal Pond Liners & Green Roofs
“...The leaves have a waxy coat and this is what makes them difficult to eradicate. However, glyphosate weed killer will eventually kill the plant after several applications. Anything with Ammonium Sulphamate would do the trick as well.....”
It's a real b#####d !!!
Join Date: Oct 2007
Location: avro country
Age: 69
Posts: 174
Just spraying it with glyphosate will not work as horsetail to give it it's correct name, (marestail only grows in water), has a natural coating of silicone so the weedkiller will just run off it. I have an allotment and we are constantly fighting this stuff.
For the weedkiller to get through you need to bruise the foliage by giving it a good thrashing with a stick or similar.
Glyphosate can take up to three weeks to start working. Then give it a 2nd dose while it is in a weakened state.
Good luck with it.
For the weedkiller to get through you need to bruise the foliage by giving it a good thrashing with a stick or similar.
Glyphosate can take up to three weeks to start working. Then give it a 2nd dose while it is in a weakened state.
Good luck with it.

Resident insomniac
Join Date: Aug 2005
Location: N54 58 34 W02 01 21
Age: 76
Posts: 1,863
Japanese Knotweed.
I am fully-trained (and certified) to inject industrial-strength glyphosate (10 times the concentration of the neat stuff you can buy in the shops) into the stems of Japanese Knotweed.
This has proven to be almost 90% effective in killing the plants - we have to wait for the regrowing stems to achieve a size capable of accepting the injection needle.
As the stands are adjacent to a river, it's not permitted (by the Environment Agency) to spray, and mechanical methods risk fragments being washed away downstream during flood conditions, so we have developed the injection treatment (which is successful - with only minor regrowth from the rhizomes):-
Japanese Knotweed Removal by Glyphosate Herbicide Injection
This has proven to be almost 90% effective in killing the plants - we have to wait for the regrowing stems to achieve a size capable of accepting the injection needle.
As the stands are adjacent to a river, it's not permitted (by the Environment Agency) to spray, and mechanical methods risk fragments being washed away downstream during flood conditions, so we have developed the injection treatment (which is successful - with only minor regrowth from the rhizomes):-
Japanese Knotweed Removal by Glyphosate Herbicide Injection
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,581
I am fully-trained (and certified) to inject industrial-strength glyphosate (10 times the concentration of the neat stuff you can buy in the shops) into the stems of Japanese Knotweed.

Join Date: Jan 2001
Location: The Burrow, N53:48:02 W1:48:57, The Tin Tent - EGBS, EGBO
Posts: 2,298
Fernytickles, I find that works sometimes as well. It's a most effective method of getting rid of vine weevil grubs in pots of compost. The formerly resident plants are usually dead anyway as the grubs have eaten their roots.
Thread Starter
Join Date: Feb 2006
Location: UK
Posts: 582
So now I know that the bloody pest in my back garden is - Japanese Knotweed, confirmed by Google Images!
Rightly or wrongly - and I'm nowhere near a river - my "solution" is to let the thing grow and then spray a systemic insecticide on to the leaves. The plant then withers and dies within a week or two and doesn't come back. Since doing this the incidence in my back garden has fallen from hundreds of growths a year to a couple of dozen.
Rightly or wrongly - and I'm nowhere near a river - my "solution" is to let the thing grow and then spray a systemic insecticide on to the leaves. The plant then withers and dies within a week or two and doesn't come back. Since doing this the incidence in my back garden has fallen from hundreds of growths a year to a couple of dozen.
Join Date: Apr 2010
Posts: 92
Stand by with a flame thrower!
And if nothing works, you might try to look at it from a different angle and decide it's beautiful. No trouble growing either, real blessing!

Resident insomniac
Join Date: Aug 2005
Location: N54 58 34 W02 01 21
Age: 76
Posts: 1,863
Originally Posted by BOAC
- my hero! All my life I've been looking for someone like you.
We have Japanese Knotweed adjacent to the highway bridge across the river - a bridge that dates back many centuries an was the only bridge to survive 'the great flood' of 1771:- Corbridge Bridge
A team of volunteers from the village are determined to prevent the Japanese Knotweed from percolating into the foundations where it would destroy the structure.
Environment Agency - Japanese Knotweed
Last edited by G-CPTN; 31st May 2011 at 20:52.
Join Date: Jan 2001
Location: The Burrow, N53:48:02 W1:48:57, The Tin Tent - EGBS, EGBO
Posts: 2,298
So now I know that the bloody pest in my back garden is - Japanese Knotweed, confirmed by Google Images!
Japanese knotweed:

Horsetail:
Join Date: Jul 2008
Location: uk
Posts: 895
you might try to look at it from a different angle and decide it's beautiful. No trouble growing either, real blessing!
Resident insomniac
Join Date: Aug 2005
Location: N54 58 34 W02 01 21
Age: 76
Posts: 1,863
If, indeed, you do have Japanese Knotweed in your garden (in the UK) then you should eradicate it, as the presence (in the vicinity of buildings) can result in refusal to issue a mortgage (should you want to sell or remortgage your property).
Mortgages refused over invasive weed - Telegraph
Homeowner turned down for mortgage due to Japanese Knotweed in garden - Telegraph
moneysupermarket.com community - Japanese knotweed
Mortgages refused over invasive weed - Telegraph
Homeowner turned down for mortgage due to Japanese Knotweed in garden - Telegraph
moneysupermarket.com community - Japanese knotweed