The treatment of Japanese knotweed by Wirral Council involves:
Taking into account specific site requirements, the Japanese knotweed will either be stem injected (particularly on sites close to water courses or other sensitive plants) with a solution of Glyphosate or sprayed using a solution of Glyphosate and Icade (Triclopyr).
If stem injection is the method chosen this will be undertaken by an appropriately trained member of staff or a contractor, the operative undertaking the work will be trained and qualified in stem injection holding the relevant NPTC PA61NJ licence.
The Knapsack spraying is undertaken by a member of Wirral Council staff who is qualified in chemical application and holds an NPTC PA6 Knapsack license.
Spraying applications take place using a knapsack sprayer and will continue for a minimum of 3 years to suppress and potentially eradicate the plant.
The council is committed to continuing with its spraying programme longer than 3 years in order to ensure that the plant is eradicated and prevent regrowth.
The spraying applications take place throughout the growing season usually from March to October and involve 3 specific spraying applications.
Spraying applications will not take place when it is raining or when there are high winds as this would render the treatment ineffective. As such specific dates are not identified where spraying can take place instead this is left to the decision of the qualified staff member.
Following treatment of Japanese knotweed the stems and plant material is either left and on site and trampled down or if absolutely necessary taken off site and disposed of by a registered contractor at a site registered for disposal.
Annual site inspections and frequent visits by maintenance teams will identify and report all new Japanese Knotweed sites on, or in close proximity to, council land.
The programme of treatment outlined above complies to and follows the Environment Agency Guidelines and Code of Practice on the treatment of Japanese Knotweed.