Posted: 27/07/2012 at 11:24
Japanese knotweed is hollow. Best way of getting the weed killer into,the plant is to cut the stem, leaving about a foot off the ground and then syringe the solution into the hollow. Once you beleive the plant is dead, It is advisable to dig up and take away the soil, as the rhizomes could still be lurking in the ground and the plant could regrow. If you cant take the soil away, then you need to dig over the ground, which may cause new growth from chopped up rhizomes, but they can be treated with weed killer eaiser. It can take several years to be sure to be rid of it completly.
For disposal, you need to contact your local authority who can tell you where to take it. Not all local authority sites will take it. You can burn it, but that can lead to other issues (ie, nuisance and/or pollution).
If the plant is only on your land you could end up causing a private nuisance if you allow it to grow on another property. It must therefore be controlled and preferably eradicated. Conversely, if you have it encroaching on you land from a neighbour, you need to work amicably together to get rid of it.
The plant is covered by the Wildlife and Countryside Act making it an offence to let it grow in the wild - this includes disposing of it which could result in it taking root in the open environment.
Japanese Knotweed can reduce the value of your house - I know one person who had his house value knocked down by ??10K when he was trying to sell it and during the survey it was discovered he had it in his garden (there from a previous owner). When he set about removing it, it was discovered to be invading local authority land, who subsequently told him to remove it and the soil costing ??7K. He then had to indemnify the new property owner against the knotweed from returning for up to 5 years.
I watched a TV programme once where somebody harvested knotweed and served it up as dish -she said it tasted like asparagus!
Good luck!