Does anyone know any contractors which can undertake treatment of JKW in the Derbyshire area (specifically Belper). It is in a pretty hard to reach area and growing between tarmac and a wall. Not really doing any major ‘harm’ at the moment, so I’m thinking spaying at the optimum time over a few seasons will be best. Ta

Keep attacking it with roundup.

http://landscaping.about.com/cs/weedsdiseases/a/knotweed_3.htm

iolo – Thats plan B.

Plan A will be a lot cheaper.

You can’t buy proper concentrate weed killers anymore over the counter, so any roundup you buy from a Garden Centre is so weak weeds just ignore it.

It worked for me over about 3 years of continual spraying.

You can’t buy proper concentrate weed killers anymore over the counter

You can buy this though. 😉

http://www.amazon.co.uk/dp/B008EQV3MQ/ref=pe_385721_37986871_TE_item

You don’t want it too strong as it will kill the plant before the weeds get it. If the weeds aren’t dead, it will just keep growing back.

Edit: I don’t mean weeds. That should say roots. It’s Friday and it’s been a long week.

before knowing what the appropriate treatment would be, how much is there? we talking a couple of plants, or a bush?

You can buy this though

Good spot, used a load of Roundup (from Homebase) last WE on the patio – weeds have got a little off colour but basically still going. In the old days you sprayed and the next day there were black stubs and nothing grew back for months if not years.

Might use that concentrate neet on the bastards….

I mix mine triple strength.
Much better than anything they sell at DIY stores.

2 biggish bushes

Cut them, they’re hollow and pour roundup inside each growth.

I get mine from the farmers merchant. pokey strong glyphosate.

fortunately never had to use it on JPK.

Interestingly I noticed that it’s “endemic” around Morzine/Les Gets. No effort made to eradicate it there.

If it’s too strong, it’s no good for knotweed.

Tordon 22k seems to have been the best – think it’s banned now though. Company called twist fix seems to sell some good stuff

injection is best, not cutting the stems as this stops the active transport.

We had the Musketeers Group come in spray treat the several large clumps on our front – they weren’t cheap – several k (luckily for us paid for by the vendor)

We had one shoot grow back a couple of years later which we put some of the round up gel on the leaves and it didn’t come back at all this year.

I’ll just keep an eye on it and stick some roundup on it if it appears again

[Edit – we’re on the notts/derby border so not too far from you]

Im not going to be able to inject / treat stems as the stuff is growing out of gap with a building 1 side and the parapet of 5m high retaining wall (above a railway line) the other. It’ll be hard enough to gain access to spray it.

Glyphosate/Roundup, 40ml/litre dilution rate and apply several times a year. The chemical is systemic, so is taken into the roots rather than the more common burn off the foliage chemicals, so results won’t appear instantly, combined with the plants resilience. We spray odd bits around the tenant farms.

Boss’s brother does it for developers down Swansea way, he uses some new mega bucks chemical, but it works with far less applications.

I’m licensed to spray and inject, apart from Tordon (which is expensive) i use Rosate 36 which when sprayed on foliage when flowering gives good results.

It may take a couple of applications but its great and cheap, £30 for 5l or £100 for 20l

If you aren’t going to grow anything else there kill it with white spirit. Just be careful you don’t burn the fence down 😕

Foundations were dug out for an electric sub-station near me, before which they killed off a large clump of JKW. All seemed okay for about five years, it has now started to regrow. What does it do in the meantime???

Is the growth in railway land? If it is report to network rail and they will cut and treat. It’s incredibly nasty stuff and very invasive. I understand the process is cut and treat on site, if the cut material needs to be transported off site it is classed as hazardous waste and should be disposed through a lincsed site (check with the environment agency). The EA also have a guidance booklet on jkw. Btw, I work for nr and we hate the stuff. Costs a bloody fortune to get rid of properly and delays projects I work on. Good luck.