Japanese Knotweed & Composting
There is a danger that rapid introduction of composting in the UK, may hasten the spread of Japanese Knotweed from home composting, however, normal commercial composting procedures should ensure that no problems occur.
Japanese knotweed (Fallopia Japonica) is defined as an invasive species under the Wildlife and Countryside Act 1981.
Even after composting this very hardy species may remain viable and spread rapidly, if even small quantities are present in green wastes.
For information on invasive, non-native weeds, the (UK) Environment Agency website is an excellent starting point click here to view their page on this subject.
The UK CIWM, Scientific & Technical Review (August 2003, Volume 4, Issue 2) contains a paper titled "Investigations into the Effect of Temperature on Regeneration of Japanese Knotweed (Fallopia Japonica (Houtt.))", by Richard Ward of Bath Spa University College (UK).
The results of the study suggest that for regeneration to be prevented a temperature greater than 55oC needs to be maintained in the compost, for at least one week.
As well run commercial composting facilities will be set to maintain just such temperatures and durations, all should be well. However, it will be a different matter for home composters who will be unlikely to be able to maintain the same high temperatures. Therefore, domestic composters should take great care not to introduce any F. Japonica into their composting vessels.
The author of the paper recommends further research should be undertaken in commercial composting facilities to confirm his findings in a full-scale commercial facility, and suggests that a small risk of spreading F. Japonica remains even after commercial composting.
(For more information we suggest a visit to the Cornish Japanese Knotweed Forum.)
|
