Japanese knotweed and giant hogweed

While the most common problem presented by invasive plant species is ecological (particularly affecting native flora and fauna), some are known to present an issue to human health or impact on the built environment. The various species commonly affect and/or monopolise brownfield, amenity, residential and commercial sites once they have become established. Two species in particular stand above all others when it comes to issues of health, disposal and/or the disruption they cause to building projects: Japanese knotweed and giant hogweed.

Treatment of both plant species can be very straightforward, provided sufficient time is allocated for the treatment, appropriate guidelines are properly adhered to and a sensible approach is adopted.

This section is maintained by Jim Glaister of The Knotweed Company.

Japanese knotweed and residential property, RICS original information paper (IP27 2012) – now replaced by PS2022

Japanese knotweed and residential property, RICS professional standard (PS2022)

Japanese knotweed: Guidance for Professional Valuers and Surveyors, Property Care Association guidance document to be read in conjunction with PS2022

Feature: Japanese knotweed and residential property: diminution in value