lga5kin

Just spoke with my missess who has dealt with JK as part of her job - Evironment Agency deals with JK and will provide advise. They have a booklet avialble from there web site giving you an idea on how best to treat it and when. Cutting back is not advised (unless very controlled i.e. 1 stem at a time & then stem injecting with herbicide) as the plant root system is massive and very SMALL bits of plant can allow the plant to root and grow elsewhere. Which is why it is such a growing problem in the UK. Treatment is long term - injecting the stem is quicker but still likely to be a couple of years. Spraying the leaves when the plant has large leaves (Aug/ Sept) can take many years ( she has know one place still cropping up after 8yrs of treatment). Or you can spay and dig it up and all the soil in a 5m block round the clump and burry it approx 6m bgl making sure it is wrapped in a liner. Missess advises - get proper advise or tell your client to - chopping it could easily spread it.....

Swinny, Try contacting your local authority (council) they should have an Environmental Scientist/Consultant within there Environmental/Planning team who will be able to advise you. I hope this helps?