Japanese knotweed help

V2001

Ok so my dream bungalowi want to purchase has knotweed which has spread from the neighbours garden into this house.
They are 2 years into a 5 year guaranteed plan in place.

My question is with herbicide treatment does it ever go away permanently? Or with treatment does it come back after a few years and can regrow?

Where its growing I would want to do a extension over that area. Is it to risky incase it grows under the extension in future?

V2001

Also at the back of the garden is this hedge which looks like bamboo(at bottom of pic). Is it bamboo? Sorry for bad pic but only one I have..

daveyjp

Photo isnt great but I cant see any knotweed on that photo.

However if it is close it won't go away unless dealt with properly.

V2001

No in the photo I'm referring to the bottom of the pics. Does those plants look like bamboo?

twoLou

V2001 said:

No in the photo I'm referring to the bottom of the pics. Does those plants look like bamboo?

It looks like Bamboo to me and the invasive type too so will be problematic to remove.

I can’t help you with the Knotweed as know nothing about it but best of luck what ever you decide to do.

Freecall

Japanese knotweed can certainly be treated effectively.  You may get some return but conventional weedkiller will deal with it.

The bamboo though is the problem, much more difficult to get rid of.

Dustyevsky

V2001 said:

They are 2 years into a 5 year guaranteed plan in place.

My question is with herbicide treatment does it ever go away permanently? Or with treatment does it come back after a few years and can regrow?

If the treatment plan is insurance-backed, it's likely to be with a reputable company and the chances of re-growth will be low. Anyway, it's not a triffid, and the horror stories of the red tops need to be viewed with a good pinch of salt. It will not grow through the foundations and floors of a properly constructed extension.

The bamboo is likely to be of the non-clumping type and these sorts do spread, but again, weedkiller, properly applied, ought to sort it out in the long term. If you're doing an extension, use the digger to get it out! I have only killed the low growing spreading bamboo with a herbicide applied in early autumn, but it didn't return. It's a job most amateurs could do with a careful approach: https://www.progreen.co.uk/problem/bamboo

prettyandfluffy

The vegetation at the bottom of the photo isn't Japanese Knotweed, it's bamboo.  I would not buy a property affected by Japanese Knotweed based on my experience as an environmental consultant.

Albermarle

The garden has got knotweed and bamboo - double trouble !

Flopfluppet

I do know that bamboo is now considered to be just as invasive as knotweed and the major concern it that you can still freely buy it in garden centres etc. A house I wanted to buy had this with a treatment plan in place but we also wanted to build in the contaminated area. The company dealing with the knotweed advised against building on the area as did the poster above. The EA should provide you with the details of the company if you haven't already been handed them, we were able to speak to the company treating the garden in question. 
We walked away from the house because of it in the end even though it would have also been our dream home. 
My husband is a landscape gardener and has been asked many times to remove the bamboo you have in the photo. He has dome it with a mini digger with the provisos that it will grow back and it always has every time.
I think you might also be better walking away otherwise a dream home could quickly become a nightmare. Sorry.

user1977

Yorkie1 said:

+1 to this. 

Can we please report spammers rather than cheer them on?