Invasive Species Services at a glance
- Invasive Species Identification
- Invasive Species Control
- Invasive Species Management Plans
- Invasive Species Clerk of Works
Invasive Species Management
Several types of plants have been designated as invasive weeds. A number of these species are land based, whilst others thrive in aquatic situations.
Some of these invasive plants are native species that flourish under ideal growing conditions, others are non-native plants that have been introduced to this country either by accident, as a consequence of commerce or brought in by collectors.
Not all non-native plant species become troublesome, but when they do they are extremely difficult to control. Native species are less of an ecological problem than non-native plants and do less physical damage. The damage caused and high cost of removal of invasive, non-native species is massive.
As an example, government statistics show that the costs for eradicating Japanese knotweed has been estimated at £1.5 – 2.6 billion and for Himalayan balsam between £150-300 million.
Responsibility
The responsibility for dealing with invasive weeds rests with the individual landowners. Under the Wildlife and Countryside Act 1981 (WCA), Illegal planting of certain invasive plant species (detailed within Schedule 9 of the Act) allowing their spread or not disposing of waste-matter correctly, can bring major penalties. Magistrates can impose a maximum penalty of £5,000 and up to six months in prison. In the most serious situations, a Crown Court can impose an unlimited fine and a maximum of two years in prison.
Japanese Knotweed
Has an extensive root system that can extend for several metres, break through hard surfaces like tarmac and penetrate the foundation of houses. Early identification and management is key to control, which is best effected by herbicide treatment.
Giant Hogweed
A potential danger to public health, giant hogweed secretes a poisonous sap. Even the slightest touch can cause swelling, blistering and severe irritation. Herbicide treatment is the most effective means of treatment, but scything and flail mowing may also be used.
Himalayan Balsam
Rapidly colonises river banks and damp ground smothering all other plants in its vicinity. In autumn it leaves banks bare of vegetation and liable to erosion. Early herbicide treatment can be effective. Mowing or strimming on a regular basis may eradicate the plant altogether.
Ragwort
Poisonous to horses and other grazing animals, causing potentially fatal liver damage. Herbicide treatment in spring and early summer is recommended. Ragwort remains toxic even when treated or wilted, so effective disposal or exclusion of livestock is a major factor in controlling it.
Australian Swamp Stonecrop
The rapid growth of this species out-competes native plants, absorbs all available nutrients and chokes ponds and ditches. Early identification is vital. Regular herbicide treatment is required. Dredging out marginal and emergent vegetation can also be effective.
Water Fern
Water Fern (Azolla filiculoides) is a highly invasive waterweed, which is listed on Schedule 9 of the Wildlife & Countryside Act 1981 and as such it is an offence to plant or otherwise its spread in the wild. It is a very small free-floating water plant that forms dense mats. It chokes water courses and can present a danger to children, pets and livestock when it completely covers the water surface, as they may attempt to walk on it, without realising there is deep water beneath. Control options comprise of either biological methods or pesticide application.
Floating Pennywort
A dense interwoven mat of vegetation quickly covers water surfaces, disrupting the ecology and amenity use. Herbicide treatments with approved adjuvants can be effective, as can cutting and removal. Waste needs to be deposited well away from the water.
