Knot weed terror

Managed to completely kill large bank of Japanese Knotweed - but still looking for answers...

Hi all,
I'm not a gardener and had only been marginally aware of Japanese knotweed before my personal experience. If someone more experienced can read this and offer any explanations as to how I was able to get rid of it so easily, it would be much appreciated.

At the end of 2010, my new Wife and I made an offer on a property in Helensburgh, Scotland where we live. The home-report mentioned knotweed and that it would have to be checked out. It was a very large and mature bank of knotweed, approximately 35 metres by 5 metres at least, and located about 30 metres from the back of the property along a railway line, owned by Network Rail. It was obviously a mature bank, and had been there for many years, and it was growing closer to the property.

We were advised that this would have a very serious impact on resale value. Fortunately we were cash-buyers, but I was thinking of future resale-ability. Research confirmed that it was now industry policy that no bank would provide finance for a property that had this problem - a major problem if we wanted to sell to a buyer who needed finance.

We looked into Japanese Knotweed removal companies before buying, sent photographs, and we got the same story from each - it would take at least 5 years of treatments during the summer and cost thousands to effect a removal.

Research in Internet forums confirmed that this was a serious problem. The property was an executry and at a good price, so I decided that even in worst-case it did cost £3k+ it would be worth the risk. We proceeded to purchase and refurbish the property.

Not being one to accept everything i read, and being a little stubborn I decided I would make some efforts to deal with the problem, which, by this time was effecting 11 other properties. I wasn't prepared to wait 5 years if I didn't have to.

I contacted the local authority - they were aware that the problem had been around for many years, but as it was Network Rail land, they couldn't do anything.

I wrote two letters to Network Rail Scotland, before getting a response. I had left them under no illusions that I considered that this was their responsibility and that the consequences of failing to act might be litigation from a number of owners (this was a bluff as the other owners didn't seem to care, or had tenants in their properties).

The response was by letter and telephone call, from a nice and understanding chap who promised they would take responsibility and would arrange for remedial works to be carried out. A few weeks later I received a call from two Network Rail works people, who arrived at my property with a chemical spray and backpack pressurised spraying lance. They explained that this would take several years of visits to have an effect as it was such a large and persistent bank. By this time I had researched the plant, the chemicals (glyphosphate) and exactly how the chemicals work at a cellular level, to inhibit the production of certain enzymes and therefore growth.

I was very unconvinced at the haphazard and rather unenthusiastic way that the young boy waved the spraying lance over the plants, whilst his supervisor watched. In 10 minutes they were gone, promising to return later that summer.

I waited for weeks for anything to happen, when I did begin to notice some browning of the areas where he sprayed - only about 10% of the total area! I thought to myself that if that was what they did it might take much longer than 5 years to eradicate.

I had also read about many other techniques of using old carpets and tarpaulins to try and retard growth - as this was through a fence and on railway land this would be impossible.

I decided that if the workman for Network Rail could spray glyphosphate, then so could I - I mean, it's not as if he did anything special or skilled - he just sprayed the plants that was it, right?

I went to B and Q and purchased a large quantity of high-concentration glyphosphate solution (undiluted). According to the container It was designed to be diluted in water to cover about 3000sqm - I only needed to cover about 175sqm. That cost £40.00. I purchased a cheap pressure-sprayer at £15.00 and some gloves, a mask and safety specs. The total was around £70.00.

I waited until the weather was forecast to be warm, dry and windless for a few days. I selected a Tuesday and proceeded to mix the solutions with just a little water, to aid absorption, and started spraying.

I didn't have access to all sides of the bank as it was on the railway. So I had to use a ladder to stand tall, and use the pressure sprayer to reach the entire bank. Over the next 4 hours every single leaf and stem was drenched in glyphosphate - top and bottom. When I finished I still had lots left, so I left it to dry for an hour or two and went back and soaked the entire bank once again.

I still had a little high-concentration glyphosphate left after the second application, so I looked for the largest stems and rhizomes poking through the fence, that looked as if they went right down to large roots. I cut them off at about half-way up and filled the hollow stems with the liquid solution, until I had none left. My hope was that the chemical would be transported right down to the sub-surface roots.

I was tired, but satisfied that I would probably make at least some difference and hoped that if I were to repeat the exercise every summer for a few years, it might speed up the process a little.

Over the next few weeks I was astounded. Whereas what Network Rail had done caused some browning and a few stems to die off, The ENTIRE bank started to die away - and quickly. Within weeks the entire landscape had changed and not a single piece of knotweed remains alive-even the parts that had started growing through the concrete.

I had tried to be careful to avoid the other plants (ivy and rhododendron) but accepted that they might be killed too - surprisingly these remained completely unaffected.

By the Autumn / Winter, all that remained was dead brush. As I write this it is April 2012 and there have been absolutely no signs of any re-growth whatsoever - now when I get an updated home report done it won't mention any knotweed and the resale problem has gone away!

This, however, left me with questions. How, when many independent persons, 'experts', companies and even my own extensive research had shown that getting rid of the Japanese knotweed would be a long, arduous and difficult process, costing thousands of pounds and taking many years, just how was I able to achieve this in matter of weeks and months with just £80 quids worth of supplies from the local DIY store, a morning + afternoon of work, completely unassisted and with basic garden tools and no specialist gardening knowledge or experience?

I appreciate that if you ask a specialist company they are going to lay it on thick that you must use their services to get a sale, and scare you with tales of regrowth and demolishing properties etc etc, but I can see from magazines and forums that other people do genuinely struggle with the problem - I am genuinely confused as to just why it was so easy and would appreciate any thoughts from those more knowledgable than I.

I was very close to signing up with a well-known national company that offers removal and a regrowth insurance product, that would have seen me relieved of several thousand pounds - I'm glad, in this case, that I did it my way.

At the end of the day, i dont think a 'professional' would have done anything different - I mean how many different ways can you hold a spray-gun?!? Granted, I probably went totally 'overkill' (using 3000sqm of treatment on just 175sqm) but - it seemed to work.

Based on my experience - I would say have a go yourself with your own research and initiative, and see what results that yields before committing to spend lots of money. If anyone wants pictures of the before, during and after (and as it is today) to satisfy curiosity, I would be happy to post them online or email them.

I'm really eager for thoughts and opinions on this - I'm nothing special and didn't do anything special so they're must be an explanation! (besides that all the hype is just a marketing conspiracy to make people buy professional knotweed removal services! Joke).

Thanks

Graeme from Helensburgh.

 

Wow,

Welcome to Gardeners Corner Graeme

What a fantastic first post

I'm so glad you've had sucess with the stuff, its a nightmare. I had heard that National Parks were using 10 times the normal strength of Gyphosate to kill it off, looks like you've hit on the right method

Keep your eye on it for a while longer yet though.

 

Hi Ziggy - thanks for the reply!

I certainly will keep a very close eye on it, but after close visual inspection I can see no evidence of regrowth, and buoyed by the fact that if I do get regrowth I will simply repeat the procedure again.

I had read somewhere that the 'incorrect' use of glyphosphate can cause the roots to go into a 'dormant' state, and can start shooting again later.

As an amateur without advanced knowledge of gardening or botany I have to accept that that might be a possibility however, I am doubtful about that advice for a couple of reasons

1) that advice was on a website selling a professional removal service, under the heading "dangers of using an amateur removal company' - obviously trying to persuade and worry people enough to buy their own services;

2) the length of time that has elapsed with no growth, and the fact that we have had a particularly warm and wet winter,rather than freezing which pauses growth activity anyway - unless someone can correct me I would have expected to see at least some tiny signs of re-growth.

At this point I am fairly satisfied that the application of such a high concentration of glyphosphate has killed the roots. That is why I have waited until now to post, so I could see if it came back.

In don't pretend to have a magic cure, and sympathise with others who do have major structural and aesthetic problems with this weed, just hope this spurs someone else on to go down to their local hardware shop and have a go!

Graeme

 

Fair play Graeme,

The brown patch at 7'o clock from the bird table is a big patch of the stuff and its not getting any smaller

 

That's great news GDEK. It's said that if you want a job done properly do it yourself, in this case that rings true!

I think it's the fact that you've been persistent with the glyphosate that's cleared the knotweed and perhaps the roots weren't that deep.

As Ziggy says keep your eye on it for any new shoots. What does seem a little worrying is that it is still on the banks of neighbouring gardens, I presume you didn't spray all those as well. Therefore it's likely to spread again to the place that you've cleared. I hope not!

 

Good work GDEK.
With your good relations with Network Rail, it might be a good idea to advise them their actions have had an effect and ask them to remove the dead foliage from their property. (we don't want you done for trespass)
Removal will make it easier to spot any new growth and re-treat it before it re-establishes.
And as Sheal suggests, keep an eye on the neighbours growth.

 

Think that is classed as toxic waste now.

 

Answer is in your first post GDEK
Helensburgh
Your greenglow has eradicated it and nothing to do with Glysophate
You have NUKED IT
Have you checked your blue badge recently :-) ?

Jack McHammocklashing

 

Is that his Disability badge - or do you mean his Radioactive monitor?

 

Hello all, I came onto this site to sign up and post some problems I have with Japanese Knotweed, but it seems GDEK has answered them for me!

Our property is bordered on all sides by land, some ours and some not. The woodland at the back of the house (not ours) has a small growth of knotweed on it, probably a dozen small shoots between 2ft and 6ft from our property. The land to one side of our property (again not ours, unclaimed land according to Land Registry) has a mass growth on it, though the majority of it is on the other side of the land. Again there are smaller shoots close to our property, which is bordered on that side by conifers.

As the land at the side belongs to no one, apparently, then no one is responsible for cleaning up the knotweed (or so say the council), therefore I'm very keen on getting in there and spraying what I can myself.

The woodland at the back, I think I will trace the landowner first as I don't want to start using powerful chemicals on land that I don't own without at least asking first!

Providing we have some good weather this weekend, I'm planning on going out and taking some photos to document the current growth, and perhaps then start immediately with spraying after a visit to B&Q!

 

Welcome to Gardeners Corner Take heed of the P.P.E. advice & make sure you've got a mask suitable for spraying.

 

Most definitely. I do have all the necessary gear already, but I will play it safe and buy some new stuff just for this to make sure I avoid any cross-contamination (especially with the gloves) - the last thing I want is to bring it onto my own land myself after having got rid of it next door!