Giant Hogweed
Heraculeum mantegazzianum
Widespread across the UK Giant Hogweed was introduced from the Caucasus region of central Asia as an ornamental plant in the 19th century.
Each plant produces thousands of seeds which spread rapidly along water courses. If the sap of Giant Hogweed gets onto your skin, it can cause severe chemical burns when exposed to sunlight.
The plant can be treated with herbicide between April and June to prevent its spread
Japanese Knotweed
Fallopia japonica
Another plant introduced as a garden ornamental in the 19th century originating from eastern Asia.
Spreading from rhizomes, the plants grow rapidly, shading out other species leading to their decline. On riverbanks when the plant dies back in autumn it leaves bare soil which is vulnerable to erosion during floods.
The plant can be controlled using herbicide by stem injection treatment.
Himalayan Balsam
Impatiens glandulifera
Introduced to the UK by the Victorians from the Himalayan region.
Explosive seed pods spread the seed of this annual plant very effectively especially along watercourses.
With no natural biocontrol measures the plant forms dense stands out-competing other native plants and reducing biodiversity.
The plant can be controlled with herbicides in the spring before flowering
INNS Strategy
The DEFRA Great Britain Invasive Non-Native Species Strategy sets out key aims and actions for addressing the threats posed by invasive non-native species.
One of the aims to encourage and support people to work together to improve co-ordination and co-operation on issues at a European and international level.
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Invasive Non-native Species [INNS] are plants, animals, fungi and microorganisms which have been introduced deliberately or accidentally to areas outside of their natural range. Some of these species can cause adverse ecological and environmental impact, with some posing a threat to human health.
As many of these introduced species have no natural biocontrol measures, they have a competitive advantage over native species. This leads to a reduction in biodiversity in areas affected and can result in physical erosion of habitat such as riverbanks as indicated earlier.
YORgreencic works with the Environment Agency and other statutory and voluntary organisations to help control some of these species on the River Aire, Wharfe and Calder. Over the years the control measures have proved highly effective in controlling INNS and promoting biodiversity in the region.
“We are commissioning a series of stories with our videographer to help demonstrate the impact of INNS on our water courses and share the success of our treatment programme.”
