Hefty, every little bit of root accidentally left in the soil can potentially regenerate into a new plant and you might end up playing whack-a-mole with new shoots coming up. Apply glyphosate while the root system is intact, and it should penetrate every inch of root and kill it dead.
"What is hateful to you, do not do to your neighbour".
Hefty. this is a reportable plant you need to inform council ASAP to start to kill cut stem approx. 60cm from ground fill hollow with weed killer and leave it will regrow so need to repeat a number of times to control it.
On building sites now if this is present they first have to use above method then remove soil down to aprox 1.5Mts this soil must not go into land fill but has to be heat treated then is kept for three years before re use in case the plant has not been completely killed off.
It is a real problem although recent research has shown that actually only about .7% of the UK has none native invasive plants so not as bad as was originally thought.
If you have a garden and a library, you have everything you need.
You do not need to inform the council if you have knotweed in your garden.
Your are really describing approaches which are appropriate for large building sites where there's a lot of ground disturbance and contaminated earth removed from site (which requires disposal at a licensed site) etc. And sites where there is adjacent habitat which cannot be subjected to spray drift. I've worked on these sorts of sites, as a landscape architect. Although control of JKW has always been referred to specialist contractors.
Hefty has a single plant possibly a seedling. (There are a couple of near relatives/hyrbrids of JKW which do produce viable seed). It's got a lot of leaf. Foliar spraying is probably going to be effective, combined with careful monitoring for regrowth and minimising any digging done in the vicinity of the plant.
Perhaps the most effective and simplest method for the home gardener to tackle Japanese knotweed is with the glyphosate-based weed killer. This is often sold as Roundup or ask your supplier for a suitable weed killer. Always carefully check the label and follow instructions when using any herbicide.
Glyphosate is usually applied to the foliage and is passed within the plant to the underground parts. It is useful to cut away old stems during the previous winter to allow good access. You must never strim areas containing Japanese knotweed.
The best time for spraying with glyphosate is at the flowering stage in late summer. However, it is difficult to spray at this stage, when the weed is 2.1m (7ft) or more high.
A more practical approach is to allow Japanese knotweed to grow to about 90cm (3ft), which will usually be reached in May, and spray then. There will be regrowth and consequently a second application in mid-summer is useful.
Check during September and if it has grown once more, spray again before growth begins to die down in the autumn. Check again the following spring.
Avoid spray coming into contact with garden plants. Glyphosate-treated knotweed will often produce small-leaved, bushy regrowth 50-90cm (20in-3ft) in height the following spring. This is very different in appearance to the normal plant and it is essential that this regrowth is treated.
It usually takes at least three to four seasons to eradicate Japanese knotweed using glyphosate. Professional contractors, however, will have access to more powerful weedkillers that may reduce this period by half.
(My post somehow crossed with Dove, good that we are basically saying the same thing!)
"What is hateful to you, do not do to your neighbour".
Thumbs up for the weedkiller approach from me. I would go for one of the stronger glyphosphate based weedkillers recommended in the RHS article linked in Dove's posting.
Don't panic Hefty - I know at least 2 people who have successfully eradicated JKW using glyphosphate & they had substantial clumps - much bigger than your single plant. The important thing is to keep on top of the spraying if it comes back.
Good luck
PS Might be worth mentioning to your neighbours so they can also be vigilant for any growth in their borders - a concerted effort from all of you will knock it for six.
Heaven is ... sitting in the garden with a G&T and a cat while watching the sun go down
Posts
Hefty, every little bit of root accidentally left in the soil can potentially regenerate into a new plant and you might end up playing whack-a-mole with new shoots coming up. Apply glyphosate while the root system is intact, and it should penetrate every inch of root and kill it dead.
Hefty. this is a reportable plant you need to inform council ASAP to start to kill cut stem approx. 60cm from ground fill hollow with weed killer and leave it will regrow so need to repeat a number of times to control it.
On building sites now if this is present they first have to use above method then remove soil down to aprox 1.5Mts this soil must not go into land fill but has to be heat treated then is kept for three years before re use in case the plant has not been completely killed off.
It is a real problem although recent research has shown that actually only about .7% of the UK has none native invasive plants so not as bad as was originally thought.
Not 'notifiable' - full legal position re Japanese Knotweed here https://www.gov.uk/prevent-the-spread-of-harmful-invasive-and-non-native-plants
and good information on how to deal with it here https://www.rhs.org.uk/advice/profile?pid=218
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
You do not need to inform the council if you have knotweed in your garden.
Your are really describing approaches which are appropriate for large building sites where there's a lot of ground disturbance and contaminated earth removed from site (which requires disposal at a licensed site) etc. And sites where there is adjacent habitat which cannot be subjected to spray drift. I've worked on these sorts of sites, as a landscape architect. Although control of JKW has always been referred to specialist contractors.
Hefty has a single plant possibly a seedling. (There are a couple of near relatives/hyrbrids of JKW which do produce viable seed). It's got a lot of leaf. Foliar spraying is probably going to be effective, combined with careful monitoring for regrowth and minimising any digging done in the vicinity of the plant.
https://www.salford.gov.uk/d/Guidance_on_control_of_Japanese_Knotweed_to_homeowners.pdf
Glyphosate
Perhaps the most effective and simplest method for the home gardener to tackle Japanese knotweed is with the glyphosate-based weed killer. This is often sold as Roundup or ask your supplier for a suitable weed killer. Always carefully check the label and follow instructions when using any herbicide.
Glyphosate is usually applied to the foliage and is passed within the plant to the underground parts. It is useful to cut away old stems during the previous winter to allow good access. You must never strim areas containing Japanese knotweed.
The best time for spraying with glyphosate is at the flowering stage in late summer. However, it is difficult to spray at this stage, when the weed is 2.1m (7ft) or more high.
A more practical approach is to allow Japanese knotweed to grow to about 90cm (3ft), which will usually be reached in May, and spray then. There will be regrowth and consequently a second application in mid-summer is useful.
Check during September and if it has grown once more, spray again before growth begins to die down in the autumn. Check again the following spring.
Avoid spray coming into contact with garden plants. Glyphosate-treated knotweed will often produce small-leaved, bushy regrowth 50-90cm (20in-3ft) in height the following spring. This is very different in appearance to the normal plant and it is essential that this regrowth is treated.
It usually takes at least three to four seasons to eradicate Japanese knotweed using glyphosate. Professional contractors, however, will have access to more powerful weedkillers that may reduce this period by half.
(My post somehow crossed with Dove, good that we are basically saying the same thing!)
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Thumbs up for the weedkiller approach from me. I would go for one of the stronger glyphosphate based weedkillers recommended in the RHS article linked in Dove's posting.
Don't panic Hefty - I know at least 2 people who have successfully eradicated JKW using glyphosphate & they had substantial clumps - much bigger than your single plant. The important thing is to keep on top of the spraying if it comes back.
Good luck
PS Might be worth mentioning to your neighbours so they can also be vigilant for any growth in their borders - a concerted effort from all of you will knock it for six.