Japanese Knotweed

suzuki1_2

I spotted 3 shoots this morning one inch high so it looks as if it has started. Did not see it yesterday. However other than that, nothing. The RHS says to wait until it is 3 foot high to spray it, to take more poison into the plant but my instinct is to spray it now. I will try and follow their advice though but I will find it hard!!

DaftyDuck

If it was treated last year, as OP alluded, it's likely to be well behind untreated clumps. The stuff on my land that's treated is inches high at most, while neighbouring landowners who are .... less careful have stuff well over thigh height.

Don't spray for a couple of months... Difficult, I know, just like a scab!!! But, resist, resist

elsien

I read somewhere it's best treated in the autumn so the chemcals are more likely to be taken right back into the roots.
I must confess to having been unable to wait that long as it got bigge and bigge.....

DaftyDuck

'Tis best treated in the Autumn.....





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......I blitzed some earlier today! Irresistible!

daveyjp

Autumn is too late as by then it is dying back.

Leave to grow fully, then treat twice in July, August and September. Had this done on three stands last year and this year nothing as yet.

I_have_spoken

All too easy to spill on way to the compost - https://www.amazon.co.uk/Mistral-Ammonium-Sulphamate-5Kg/dp/B004MMTVJI

Davesnave

elsien wrote: »

I read somewhere it's best treated in the autumn so the chemcals are more likely to be taken right back into the roots.....

If injecting, yes.

Otherwise, probably no advantage, as growth activity will be slowing down.

elsien

Yes. I decided to try injecting it last time to see if it was more effective. Bit of a faff though and I'm not sure how much actually went in so it's a wait and see at the moment.

Jojo_the_Tightfisted

I'm cynical. I suspect the letter was to try and establish a paper trail saying that the knotweed is coming from your property, so that they can try and make you pay for removal on their land.

If you could afford it, I'd suggest you saw a solicitor to make it very clear to them that this is not your responsibility, you have dealt with any on your land prior to their unauthorised entry onto your property, they are not to trespass on your land again under any circumstances, but if they were to contact you in a polite, respectful manner in good time (so giving x number of days'/weeks' notice), you would be happy to consider making arrangements with them for gaining access at a time that suits you.