Japanese Knotweed hotspot: Is your home safe from the plant?

Growing up to three metres tall with roots reaching down 20 metres, the plant is known for wreaking havoc on homeowners.

Invasive plant specialist Environet UK has now revealed the number of Japanese knotweed hotspots across the county this spring.

And Arran tops the list for North Ayrshire, with 42 of the plans already identified within 4km of Brodick alone, as well as 56 within 4km of Lamlash and 56 within the area around Glenkiln.

On the mainland,  Irvine appears to be worst hit by the plant with 11 cases of Japanese Knotweed identified within 4km of the town.

The records show Kilwinning had an estimated five cases, the Three Towns had six cases, West Kilbride had seven, Kilbirnie four, Dalry three, seven in Millport and six in Largs.

Some parts of Glasgow have recorded 138 sightings of the plant within 4km. While in London, some parts have recorded 265 sightings of knotweed.

While it hibernates over Winter, from March and April it returns and can destroy pipework, drains and can even weaken building foundations.

Japanese Knotweed (Image: Environet)

Environet UK's Japanese Knotweed Heatmap was designed to inform homeowners and homebuyers of the presence of the destructive plant and the risk to their property.

The data is generated from over 50,000 known infestations and it adds new sightings daily.

Not only is Japanese Knotweed notorious to get rid of but it is also tricky to spot.

Its appearance changes with the seasons so you need to be aware of what the plant looks like at different times of the year.

Environet says that it is easier to spot Japanese knotweed during the spring and summer months.

These are the key traits you should be looking out for:

• Red shoots emerge in spring that look like asparagus
• Leaves which are shield or shovel-shaped
• Stems that resemble bamboo canes with purple speckles
• Small, cream-coloured flowers developing towards the end of summer

In contrast, as we move into Autumn later in the year, you should look for yellowing leaves that wilt as we head into winter.

The stems will also change to a darker brown before it becomes dormant in winter.

Japanese Knotweed is often mistaken for other plants including Bindweed, Himalayan balsam, Russian vine and more. 

You can learn more about how to identify Japanese knotweed via the Environet website.