Invasive Species Consultants

We are invasive Species consultants with years of experience in the recognition of Japanese Knotweed and Giant Hogweed. We will advise on the presence of the species and the methods of control but do not carry out the control methods ourselves.

General Invasive Species Information.

Japanese Knotweed

Japanese Knotweed, (Fallopia Japonica) {JKW} is a non-native invasive species of plant. The plant is an extremely long-living perennial that does not spread by seeding. Instead it spreads by vegetative means. Any small section of the rhizome will grow into a new plant. It is an extremely vigorous invasive species and very difficult to eradicate.

Under section 14 and Part II of Schedule 9 of the Wildlife and Countryside Act 1981 it is an offence for it to be planted in the wild or otherwise caused to grow in the wild. Any area where japanese knotweed is found should be fenced off and warning signs erected. All staff should be warned both verbally and in writing that these areas should not be entered and should not be tracked over by machinery.

If land that is contaminated with japanese knotweed is required to be worked on or is in danger of being tracked over or affected by the construction works in any way it must be dealt with in a rigorous way. Failure to do so not only risks prosecution but very high costs to eradicate any new growth.

There does not appear to be any defined distance away from japanese knotweed that work should be carried out. Literature does state that the underground root system can spread up to seven metres and this is the suggested size of area to be excavated when eradicating by excavation. All excavated soil must be treated as controlled waste and dealt with according to strictly controlled procedures.

Alternatively Japanese Knotweed can be controlled by a prolonged treatment with approved herbicides.

It is not an offence to leave japanese knotweed growing, in situ, only to spread it to new areas.

Giant Hogweed

Giant Hogweed is an invasive species common in the UK that is associated with both occupational health and environmental problems. Giant Hogweed is common along roads, footpaths, railway lines, rivers, wasteland, demolition sites and agricultural areas.

Giant Hogweed produces approximately 1500 seeds per flower head in late summer.

Under section 14 and Part II of Schedule 9 of the Wildlife and Countryside Act 1981 it is an offence for it to be planted in the wild or otherwise caused to grow in the wild. Any area where Giant Hogweed is found should be fenced off and warning signs erected. All staff should be warned both verbally and in writing that these areas should not be entered and should not be tracked over by machinery.

If land that is contaminated with Giant Hogweed is required to be worked on or is in danger of being tracked over or affected by the construction works in any way it must be dealt with in a rigorous way. Failure to do so not only risks prosecution but very high costs to eradicate any new growth.

There does not appear to be any defined distance away from Giant Hogweed that work should carried out. Literature does state that the seeds from the plant can spread up to four metres and this is the suggested size of area to be excavated when eradicating by excavation. All excavated soil must be treated as controlled waste and dealt with according to strictly controlled procedures.

Alternatively Giant Hogweed can be controlled by a prolonged treatment with approved herbicides.

It is not an offence to leave giant hogweed growing, in situ, only to spread it to new areas.