Japanese Knotweed

shazza 3

Hello. Having had a major problem in the past with this noxious plant, I was astounded to read in one of the daily papers that scientists in one of the universities had done a study and now claim that this plant is not as bad as we all thought !!! They had dug up the whole plant/root, left them to dry out then replanted it (for reasons known only to them) and said they were now harmless. I was puzzled because why would you want to replant it (to see if it re-grew ??). Anyway I don't believe a word of it because it took us years to get rid of it in our garden. The scientists need only visit Wales to see how invasive it is. My OH said Buddleia is just as bad as that grows through derelict buildings/chimneys as well 

Dovefromabove

Yes the bit they’d dug out had died … but what about all the bits of root they’d left behind in the soil?  That’s the real problem. 

wild edges

Were they testing how plant material could be disposed of? IE, instead of expensive disposal methods could it just be dried or burned instead? It would make sense that they tried to replant the dried material to see if it was now inert if that was the case. It doesn't treat the problem but it would prevent a lot of fly tipping if there was a cheaper disposal method.

Fairygirl

The common species Buddleia has nothing on Knotweed. 

jonathan.cole

I think this is the study your article was probably based on:

https://peerj.com/articles/11783/

They were looking at what size and type of material is needed for regrowth and if dessication was a good control strategy. It seems dessication does kill it and small fragments can regrow if they have a node.

None of this seems particularly controversial but is useful additional info for managing Japanese knotweed.

I don't know whether you have misunderstood or the papers are up to their usual business of just straight making up nonsense vaguely inspired by research studies to give people a nice little outrage hit.

bédé

Japanese knotweed is not a plant it's a problem.

Fairygirl

There's been good success up here by injecting weedkiller directly into the stems. They've done various trials over the last few years with this method.

My ex hubby had a serious infestation nearby in his new house. Eradicated now with a bit of effort.

BobTheGardener

Fairygirl said:

There's been good success up here by injecting weedkiller directly into the stems. They've done various trials over the last few years with this method.

My ex hubby had a serious infestation nearby in his new house. Eradicated now with a bit of effort.

Yes, but how's the knotweed?

Fairygirl

BobTheGardener said:

Fairygirl said:

There's been good success up here by injecting weedkiller directly into the stems. They've done various trials over the last few years with this method.

My ex hubby had a serious infestation nearby in his new house. Eradicated now with a bit of effort.

Yes, but how's the knotweed?

  

shazza 3

it's going to take an awful lot of people to inject every single stem with weedkiller here in Wales. The stuff is absolutely rife. The council don't seem interested in clearing it and they don't even cut back overhanging trees into the road anymore either. We live behind a field where there's a telecoms mast situated and the field is absolutely overgrown with brambles/buddleia/weeds etc. The fence surrounding the field now has brambles growing through it onto the pavement and further down the road, there are trees that are sprouting through the fence too. I asked the council about cutting back the brambles and they said they have to establish whether the land is council owned first !!!! Even though you have to dodge out of the way when walking on the pavement, it's a nightmare. I do regularly cut back anything that overhangs my property but the old lady living further down the road is unable to do this due to a frozen shoulder and I can't reach it either as her back wall is too high.     

Fairygirl

It would need a lot of people here too  
A big area would be virtually impossible to clear easily, but what I meant was that they'd done trials in various areas, and it was the method that worked effectively. I haven't heard any updates though - it was a number of years ago.
Mind you, they've proabably got their hands full with Himalayan Balsam and bl**dy rhodo ponticum - an even bigger curse up here.