Japanese Knotweed: Asbos for failure to control invasive plants

Very invasive plant and can be hard to kill. The normal off the shelf weedkillers take a long time to get down to the root and work. It spreads like wildfire too. I believe you cannot just dig the stuff up because of the way it can spread. The root needs to be killed. Repeat spraying weakens it and eventually it will die off.
I used to work in a garden centre many years ago and it was a common question that we were asked. Normal weedkillers take a long time to kill off a well established plant. Better to get someone in with a spraying licence so a stronger substance can be used.
Big Al is right but you can start early before it flowers when it is in its growing period. Keep spraying from April through to September during the growing and flowering period.

 

Japanese Knotweed and Himalayan Balsam really are major pests. Very difficult to get completely rid of them.

 

I remember an article appearing in Steam Railway magazine about the problem. I don't seem to have a copy anymore but that had some very interesting points about removal and the plant itself

 

Tell me about it. I've spent the last two years trying to clear Himalayan Balsam from 400 yards of river bank,and 200 yards back onto the land behind, on the River Alyn in Flintshire. So much work involved I've not had a railway related day in the past 5 months. Pulling it up is the best remedy ,and it comes out easily enough, but it's back breaking work. You can't legally spray within a certain distance of a river as it can pollute the water. At least I get to see the Class 60s on the Dee Marsh workings. Watch out Llangollen Railway,it's not far from you!

 

@mickpop
My thoughts with you on that one! Thankfully never had to weed the stuff myself and with not being able to spray either it must seem like a thankless task at times I presume?

 

One of our volunteers has just bought a house behind Pentrefelyn C&W between the Canal and River, where the river side of it has quite a bit of knotweed. Luckily for him the law states that those selling the property have to pay for treatment of it. One to watch out for if your selling a house or land, as he said to me it was £7000 or so for the course of treatments to be done.

 

Wow. Now that is expensive although I imagine those in the know would add that to their house price perhaps?

 

So what will happen when it is found on citizen owned land which is looked after by civil servants.

 

There was a great amount of this type of virulent weed on a landfill site in this area, which is in an area of scientific interest. The local authority have dealt with it - but I don't know how t was done.

 

A few years ago I noticed a big clump of Japanese knotweed on some fallow land near my house. The landowner lives miles away and getting them interested (even if I'd got DEFRA involved) would have been a lengthy nightmare, throughout which the plant would have been spreading like mad. So I dealt with it myself. I looked up the DEFRA guidelines and liberally sprayed it once a month in July, August and September with glyphosate weedkiller. It took three years, but it worked. I still check the site three or four times a year now, just in case.

Three things to note:
1. DO NOT pull up Japanese knotweed! Even if you drop a tiny piece of the root, it will re-grow and at do so an alarming pace! Trying to pull it up is just a recipe for spreading it even more.
2. You MUST use weedkiller with glyphosate, because that's the only sort that kills the roots of the plant.
3. If you're going to spray these plants when in flower, please be VERY careful that you don't poison all the wildlife that may be on it when you do so. Remember that we humans are only one form of animal life on t'planet.

Getting rid of these plants needs patience, but it can be done.

 

another unseen problem looming is Ash Die Back...already in Dorset and heading bin all directions...a lot of trees will be removed......

nick

 

I've had some experience in invasive weed bashing and it is very hard work.
Knotweed is the only one that you have to treat with glyphosate, digging it out just spreads it further.
I've hand pulled ragwort and H.Balsam - the ragwort was on farmland and was burnt using hay and brushwood from hedge-laying. The H.balsam is much easier to uproot and getting both before they set seed is the knack to effective clearing, but it can take several sessions.

 

Incidentally, contrary to popular belief it is still legal to plant this stuff on your own land; what you're not allowed to do is release it into the wild. Type the Latin name - Fallopia japonica - into the RHS Plant Finder and it will point you in the direction of several nurseries which continue to sell it. It's a barmy situation.

 

First introduced in the 1800s for the well to do as it thrives in this climate. It is silly that you can still buy the plant in many places but then you would expect the owners of the house to plant it and keep it trimmed and not spread out.