Japanese Knotweed and other invasive or harmful plants
Resources
Introduction
Home and Landowners have a responsibility to prevent harmful weeds on their land spreading onto a neighbour’s property, and to prevent invasive, non-native plants on their land spreading into the wild and causing a nuisance.
Home and Landowners have a responsibility to prevent harmful weeds on their land spreading onto a neighbour’s property, and to prevent invasive, non-native plants on their land spreading into the wild and causing a nuisance.
One invasive non-native plant particularly prevalent int his country is Japanese Knotweed. It can grow as much as 20 centimetres per day, through tarmac and cause structural damage to property, if uncontrolled, can cause extensive damage to property. It spreads rapidly via a root system that extends to at least 2m deep. Small fragments of root will regenerate into new plants.
Another, Giant Hogweed, can cause harm to human health.
The Government has set up a website to help identify such plants. The link can be found in the Additional Resources section below.
Harmful Weeds
A number of weeds are a danger to animals, or cause problems for agricultural production if left to spread unchecked. The following weeds are controlled by law:
A number of weeds are a danger to animals, or cause problems for agricultural production if left to spread unchecked. The following weeds are controlled by law:
- common ragwort
- spear thistle
- creeping or field thistle
- broad-leaved dock
- curled dock
It’s not an offence to have these weeds growing on your land, but you must:
- stop them spreading to agricultural land, particularly grazing areas or land used for forage, like silage and hay
- choose the most appropriate control method for the your site, e.g. if it is a protected site
- not plant them in the wild
If you allow these weeds to spread onto someone else’s property, you could be served with an enforcement notice. You can also be prosecuted if you allow animals to suffer by eating these weeds.
Invasive, Non-Native Plants
You must not plant in the wild or cause certain invasive and non-native plants to grow in the wild. This can include moving contaminated soil or plant cuttings. If you do, you can be fined or sent to prison for up to 2 years.
The most commonly found invasive, non-native plants include:
You must not plant in the wild or cause certain invasive and non-native plants to grow in the wild. This can include moving contaminated soil or plant cuttings. If you do, you can be fined or sent to prison for up to 2 years.
The most commonly found invasive, non-native plants include:
- Japanese Knotweed
- Giant Hogweed
- Himalayan Balsam
- Rhododendron Ponticum
- New Zealand Pigmyweed (this is banned from sale)
You’re not legally obliged to remove these plants or to control them. However, if you allow Japanese Knotweed to grow onto other people’s property you could be prosecuted or sued for causing a private nuisance.
Japanese Knotweed and damage to properties
Left uncontrolled, Japanese Knotweed can quickly dominate a garden and spread to adjoining properties. It can also spread into foundations and boundary walls. Common problems caused by knotweed are:
Left uncontrolled, Japanese Knotweed can quickly dominate a garden and spread to adjoining properties. It can also spread into foundations and boundary walls. Common problems caused by knotweed are:
- Damage to paving, tarmac, driveways, etc
- Damage to walls, foundations, etc. (knotweed has been discovered growing under suspended floors with minimal light)
- Shading of light to windows and gardens due to height of growth
- Damage to flood defence structures
- Damage to archaeological sites
- Displacing of native flora and fauna
- Reduction in land and property values
- Increased risk of flooding through dead stems washing into river and stream channels
- Increased risk of soil erosion and bank instability following removal of established stands in riparian areas
- Restriction of access to riverbanks for bank inspection and amenity use
- Accumulation of litter in mature stands
- Aesthetically displeasing
Legal sanctions
The Weeds Act 1959 introduced controls over the spreading of injurious weeds. Sanctions have been added to over the years and the Wildlife and Countryside Act 1981 states that you must not plant in the wild or cause certain invasive and non-native plants to grow in the wild. This can include moving contaminated soil or plant cuttings. If you do, you can be fined or sent to prison for up to 2 years.
In Scotland, this has been amended by the Wildlife and Natural Environment (Scotland) Act 2011.
The Weeds Act 1959 introduced controls over the spreading of injurious weeds. Sanctions have been added to over the years and the Wildlife and Countryside Act 1981 states that you must not plant in the wild or cause certain invasive and non-native plants to grow in the wild. This can include moving contaminated soil or plant cuttings. If you do, you can be fined or sent to prison for up to 2 years.
In Scotland, this has been amended by the Wildlife and Natural Environment (Scotland) Act 2011.
The Government has now introduced procedures, including the right to issue anti-social behaviour orders (ASBOs), in order to control invasive alien species such as Japanese Knotweed.
The Anti-social Behaviour, Crime and Policing Act 2014 empowers local councils and the police to issue community protection notices to require someone to control or prevent the growth of Japanese Knotweed or other invasive non-native plants that are capable of causing serious problems to communities. The test is that the conduct of the individual or body is having a detrimental effect of a persistent or continuing nature on the quality of life of those in the locality, and that the conduct is unreasonable.
Under the Act, conduct includes a failure to act. Local authorities and the police will be able to place restrictions on a person’s behaviour and, if necessary, force them to take steps to rectify their behaviour if an individual, or organisation, is not controlling Japanese Knotweed or other invasive plant and could be reasonably expected to do so. Conviction under the Act would be a criminal offence and individuals could be fined up to £2,500, with companies facing fines of up to £20,000.
Further powers to the environment authorities to enter into species control agreements (SCA) with owners of premises where the authority considers that an invasive non-native species is present. The Infrastructure Act 2015 empowers the environment authorities to make species control orders (SCO) if the owner of premises fails to comply with or agree to an SCA. The SCO would require the owner to carry out species control operations or allow the authority to do so itself.
Eradicating Japanese Knotweed and other such plants
There are different methods for eradicating these plants.
One method is to cover them and deprive them of sunlight. You could buy some very large plastic tarpaulins or to use old carpet to cover the patch of Knotweed in early Spring. Make sure there are no gaps in the covering and that the edges are weighted down. Any new shoots that manage to grow can be crushed by walking on them.
There are different methods for eradicating these plants.
One method is to cover them and deprive them of sunlight. You could buy some very large plastic tarpaulins or to use old carpet to cover the patch of Knotweed in early Spring. Make sure there are no gaps in the covering and that the edges are weighted down. Any new shoots that manage to grow can be crushed by walking on them.
There are also herbicide treatments that can be applied. Spraying with herbicide is an effective treatment to stop invasive plants from spreading. You will have to re-spray. It usually takes:
- 3 years to treat Japanese knotweed until dormant
- 15 years for giant hogweed seeds to stop germinating
When using some herbicides you may need to:
- make sure anyone spraying holds a certificate of competence for herbicide use or works under direct supervision of a certificate holder
- carry out a Control of Substances Hazardous to Health (COSHH) assessment
- make sure you only use approved herbicides – find out more about pesticides
- dispose of surplus chemicals legally
- get permission from Natural England if the area is protected, eg sites of special scientific interest
- get permission from the Environment Agency if the plants are near water
Disposing of the plants and any herbicides
To dispose of certain plants and herbicides, you may also need:
To dispose of certain plants and herbicides, you may also need:
- an environmental permit
- registered waste exemption
- trade effluent consent
You may be able to bury the plants, but first check with the Environment Agency to see if this is allowed. You may need to inform the EA a week before you intend to bury the plant waste.
If Farmers are thinking of burning non-native invasive plant waste they must tell the EA at least a week before and their local environmental health officer . Businesses may also need an environmental permit or registered waste exemption.
If you’re burning privately as an individual, you don’t need to do this but you should check with your local council that burning is allowed.
Off -site disposal – Soil or plant material contaminated with non-native and invasive plants can cause ecological damage and may be classified as controlled waste. It’s an offence to keep, treat or dispose of waste that could harm the environment or human health.
Soil contaminated with some persistent herbicides (herbicides that don’t break down), and Japanese Knotweed itself, are classed as hazardous and may need to be dealt with by a specialist contractor. You must use a licensed waste carrier and an authorised landfill site.
Useful Contacts
Further information can be found on Government websites and the GB non-native species secretariat, links can be found in the Additional Resources section at the end of this subject.
Further information can be found on Government websites and the GB non-native species secretariat, links can be found in the Additional Resources section at the end of this subject.
GB Non-native Species Secretariat
Animal and Plant Health Agency
Sand Hutton
York
YO41 1LZ
Email: nnss@apha.gsi.gov.uk
Natural England
PO Box 2423
Reading
RG1 6WY
Email: cs.reading@naturalengland.org.uk
Telephone: 0300 060 1112
Environment Agency
National Customer Contact Centre
PO Box 544
Rotherham
S60 1BY
Email:enquiries@environment-agency.gov.uk
Telephone: 0370 850 6506
Rural Payments Agency
PO Box 69
Reading
RG1 3YD
Email: ruralpayments@defra.gsi.gov.uk
Telephone: 03000 200 301
