Invasive Species

  • Qualified surveyors
  • Competitive pricing
  • Pragmatic solutions

Smart Ecology offer a range of invasive species services for species including Japanese knotweed from £290.*

The spread of invasive species is controlled by the Wildlife and Countryside Act 1981 (as amended). Although it is not illegal to have invasive plant or animal species on your site, it is illegal to cause invasive plant species to spread, or to release or allow invasive animals to escape into the wild.

Surveying early for invasive species ensures that your project or development complies with wildlife law and identifies any unforseen invasive species which could economically impact upon a business.

What we offer:

  • Invasive species surveys and assessments, including GIS mapping
  • Advice on control and management
  • Preparation of method statements for the treatment and eradication of invasive species

Request an Invasive Species Quote

* Excluding VAT. Guideline price is for a small, local site. Actual costs are based on various factors including site size and travel distance, get a free quote.

Not sure exactly what you require? Our experienced ecologists will provide free, no obligation advice, just ask.

The Process

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Invasive plant surveys


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Invasive plant species can cause harm to infrastructure, buildings, people and the natural environment. Section 14 of the Wildlife and Countryside Act 1981 (as amended) makes it an offence to plant or otherwise cause to grow in the wild (i.e. spread) invasive plant species listed in Part 2 of Schedule 9 of the Act. These species include Japanese knotweed, Himalayan balsam and giant hogweed. Although it is not an offence to have Schedule 9 invasive species growing on your land, an offence would be committed if they were allowed to spread. Additionally, under the powers of the Anti-social Behaviour Crime and Policing Act 2014, a Community Protection Order can be issued requiring individuals or organisations to control invasive plants if they are having a detrimental effect on the quality of life of those in the locality. Furthermore, the Environmental Protection Act 1990 makes it an offence to deposit, treat, keep or dispose any waste from Schedule 9 species in a way which could propagate the species and cause environmental harm.

Smart Ecology carry out surveys for Schedule 9 species as well as other non-native invasive species not listed in the legislation. Our results are provided in detailed reports, inclusive of GIS mapping showing the distribution and extent of invasive plant species. We also provide advice, mitigation strategies and management plans for the control and/or eradication of invasive non-native plants.

Surveys for invasive plant species are best undertaken during the growing season between April and October.

Among the key invasive non-native plant species are:

Japanese knotweed (Fallopia japonica)

Japanese knotweed is an extremely invasive large perennial with characteristic hollow, zig-zag stems, growing to a height of 3-4 m during a single growing season. Originally introduced as an ornamental garden plant, it is now widespread across the UK in both urban and rural areas, particularly on disturbed land. It spreads rapidly, forming extensive stands, and is difficult to eradicate as even very small parts of the root, stem or crown can grow into a new plant. Japanese knotweed has been associated with damage to hard landscaping, buildings and other structures, and supresses the growth of native plant species leading to the loss of valuable wildlife habitats. Giant knotweed (Fallopia sachalinensis) and a hybrid of Japanese knotweed and giant knotweed (Fallopia x bohemica) also occur, both of which are larger plants than Japanese knotweed, growing to 4-5 m. Although Japanese knotweed does not produce seed in the UK and giant knotweed almost always produces sterile seeds, their hybrid is fertile which poses additional problems with its control and eradication.

Himalayan balsam (Impatiens glandulifera)

Himalayan balsam is an invasive annual which rapidly colonises waste ground and damper habitats, particularly along watercourses and around ponds and lakes, forming extensive stands. Originally introduced as a greenhouse plant by gardeners, it is now widespread across lowland areas of the UK. It spreads by seed, which burst explosively out of the fruit capsules when ripe, and can spread long distances by floating along watercourses. The main impacts of Himalayan balsam are environmental; it shades and supresses the growth of native vegetation leading to the loss of wildlife habitat, and can lead to the erosion of watercourse banks when the plant dies back in the winter.

Giant hogweed (Heracleum mantegazzianum)

Giant hogweed looks similar to cow parsley, but lives up to its name as a giant by growing up to 5 m tall, with flowers up to 80 cm wide and leaves 1 m or more across. Its hollow stem is bristly and purple blotched when mature, and it forms a rosette of leaves in its first year, before flowering in the following year. Giant hogweed has a widespread distribution in lowland areas, and is usually found alongside rivers, on waste land or rough pasture. A single plant can produce up to 100,000 seeds, which are spread along watercourses, by footwear, vehicles or in contaminated soil. Giant hogweed can form dense stands and suppress the growth of native vegetation, resulting in a loss of wildlife habitat. Additionally, its toxic sap can cause long-term skin irritation and blistering.


Invasive animal species can have significant economic impacts, for example signal crayfish predating fish eggs in commercial fisheries. They can also cause ecological damage, such as the predation of the native water vole by American mink. Section 14 of the Wildlife and Countryside Act 1981 (as amended) makes it an offence to release or allow to escape into the wild non-native animal species listed in Part 1 of Schedule 9 of the Act.

Some of the most commonly encountered invasive animal species include American mink, signal crayfish and zebra mussels. We carry out surveys for non-native animal species and provide detailed reports, inclusive of mapping showing the distribution and extent of invasive animal species using GIS. We also provide advice, mitigation strategies and management plans for the control and/or eradication of invasive non-native animals.

Optimal times for surveys of invasive animals are species specific – please contact us for more information.