Japanese Knotweed

Werdnal

SnooksNJ wrote: »

On one of the sell my house shows the garden was overgrown with JK and they just mowed it all down. Personally, I thought it was unethical though.

Are you sure? would be interested to see this programme?

There is another rife plant called Hymalayan Balsam, which grows several metres tall every year, but is not the same. It can easily be pulled up, very shallow rooted, and is not an issue with mortgages and property damage. Many people get the 2 confused - we have a local dog walker here who regularly pulls up the plants and chucks them in the road if she sees them in the hedgrows - one day she said to me "That knotweed stuff is a real menace, and I pull it up at every chance" - its Balsam my dear (I thought), but you carry on anyway!

originalmiscellany

My parents have it in their abode, where it has happily lain for the past 20 years, not moving forward by more than about 1 metre. They regularly chop it back and put poison down and it's pretty okay. My sympathies to you though re your house. It's not a nice thing to deal with.

daveyjp

lessonlearned wrote: »

That's good news. A word of warning - the blasted stuff can lie dormant for as long as 20 years. Yes I did a lot of research....

I guess you just have to do regular inspections and then pounce if you see any regrowth.

Apparently the rhisomes can grow a metre a month during the growing season and a 1cm piece of rhisome can turn into a new plant in 10 days.

Vigilance is the watchword.

I've been watching a patch grow as I pass it most days. A month ago it was just out of the ground, a few new leaves. It is now a thick patch, at least 20m long and over a metre high.

Last year I saw a 'landscaping' company merrily attacking it with a strimmer! If I see him this year I'll stop and give him some advice as this area of his 'landscaping' knowledge is obviousy lacking.

rrtt

What a nightmare, who needs fictional Triffids! so sorry for the original poster, hope you get it sorted. Is this widespread thru the UK or just some areas? Here we have wild raspberry canes gone nuts, also spread like wildfire and difficult to eradicate.

*runs hastily outside to check garden*

Werdnal

rrtt wrote: »

What a nightmare, who needs fictional Triffids! so sorry for the original poster, hope you get it sorted. Is this widespread thru the UK or just some areas? Here we have wild raspberry canes gone nuts, also spread like wildfire and difficult to eradicate.

*runs hastily outside to check garden*

But wild raspberry canes don't grow through tarmac and concrete and undermine foundations.

Google it so you know what it looks like! It is quite common, brought in to the UK as an ornamental plant by the Victorians I believe, but as there are no natural predators in this country, and a milder climate that its native origins it grows like wildfire. It is a reportable weed and specialist contractors are required to eradicate it in certain areas. They dig down to over a metre and sieve the soil to remove even the smallest fragments of roots, and it is all burned. I think it is OK to strim it as long as it is in a contained area, and the trimmings are dealt with correctly as it will survive and stay dormant until conditions are right for it to grow again. Strimming it off like th eposter mentioned above, to "hide" it from prospective buyers is obviously not on! Transporting the waste to a compost heap or landfill is also not a good idea!

Spraying with herbicides will do the same job over a longer period as long as they are applied regularly and regrowth kept in check.

A lot of it spreads due to people dumping garden rubbish. There was a feature on TV last weekend about a walled garden somewhere in the UK who "inherited" some in some infected topsoil they brought in. They have fenced off the area infected with it, as they fear people will carry small fragments on their boots and spread it further.

There is a horticultural research lab in the UK who have highlighted 2 natural predators from the area of origin, that they believe will survive in the UK climate, and are trialling them as a way to control it in future.