A new biological control is being considered as a way of controlling one of Britain and Ireland’s most pernicious weeds, Japanese Knotweed, according to this story in The Guardian.
a species of jumping plant lice, aphalara itadori, could bring down the mighty knotweed by guzzling its sap. If released to do its worst, it would be the first ever “biological control” deliberately introduced into Britain.
At present, knotweed can only be controlled with heavy-duty chemicals, and then only with great difficulty- it can remain dormant under the ground even after being cut for over a decade, and chews its way through concrete and tarmac for breakfast.
It is becoming a serious threat in Ireland however and there needs to be a concerted effort to educate how to stop its spreading. Take good note of the advice given in the above article:
And how to tackle it
• Don’t ignore it. A small Japanese knotweed plant quickly becomes a major infestation. • Do not strim, flail or chip it. It can reproduce from tiny fragments of rhizome, twig or even leaf. It is extremely unlikely you can eradicate it by digging it out, because the roots stretch down so deep into the soil. • Herbicides can check its growth but only the most powerful chemical treatments will eventually clear it. These are unsuitable for spraying near water. One approach is to allow the weed to grow to about 1m, in early summer, and spray then. You will need to re-spray regrowth in midsummer and again in September if necessary. Another approach is to cut it back and apply to the stumps a powerful weedkiller such as Roundup’s treatment for tree stumps and roots. • Be careful not to allow cuttings into any drains, streams or waterways. • Do not compost cuttings or put them in the rubbish bin. It is an offence under the Wildlife and Countryside Act to cause Japanese knotweed to grow in the wild so if you dispose of it carelessly you will be breaking the law. Do not dump it in the garden waste bin of your local recycling centre. Japanese knotweed (and contaminated soil) is classed as “controlled waste”, which means you must only dispose of it at certain, licensed landfill sites: check with your local council. If you are allowed to have a fire, burning the waste on site is another way to dispose of it. There are also commercial companies that specialise in the eradication of Japanese knotweed. • More advice at environment-agency.gov.uk
