A new initiative by Horticulture.co.uk is urging members of the public to be on the lookout for cases of Japanese Knotweed in their local area.

Horticulture Magazine
September 17, 2021

Research revealed a significant growth in confirmed cases across Scotland, with many more cases likely to have gone unreported.

What Impact Does It Have?

The invasive plant is known to stifle native vegetation and its rapid growth can cause structural issues with property and waterways. Its dense growth will often shade out ecosystems reliant on sunlight and negatively impact local wildlife – with aquatic organisms particularly affected.

The rhizomes often spread inland via waterways and once established, the plant is incredibly difficult to completely eradicate.

Along with the impact on our environment, Knotweed can also cause issues with buying and selling your home – with many lenders requiring an insurance-backed guarantee for affected properties.

Identifying Japanese Knotweed Cases

A new interactive UK Japanese Knotweed map aims to help readers understand the number of confirmed Japanese Knotweed cases in their local area – with guidance on how to identify the plant based on its appearance.

Knotweed can grow several metres in height

In particular, we would recommend looking out for the red/purple-coloured shoots that grow out of the ground in Spring. Lobed green leaves will grow from these shoots which can often reach a few metres in height by the end of summer. The plant will then flower in late August / September, with cream-coloured blooms that don’t usually last long.

Japanese Knotweed

The cream-coloured blooms in late summer are fairly distinctive

How Can I Report New Cases?

For those who do find knotweed in their local area, members of the public should report these to their Local Environmental Records Centre (or ‘LERC’). The ALERC Finder allows you to easily find a suitable records centre depending on the location of the case.

The reporting of new cases is crucial as it allows environmental bodies to undertake research that helps us to understand how invasives spread. This research can then be used to develop management programmes to help prohibit its growth in your area.


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