Dealing with Japanese knotweed can be a daunting prospect when faced with the possibility of it on your site or land
Wendy O’Neill, an environmental scientist at Binnies, has recently obtained the accreditation of Certified Surveyor in Japanese knotweed, which is recognised by leading environmental bodies. The certification demonstrates a recognised level of expertise and ensures that certified surveyors are equipped to identify Japanese knotweed and provide management expertise, including overseeing eradication programmes.
This qualification is a testament to Wendy’s experience in undertaking management practices such as spraying and stem injecting Japanese knotweed as a method of control. It also allows her to provide quality assurance for clients during Japanese knotweed excavation to eradicate the species, which is usually undertaken on large projects. With Wendy’s expertise clients can be assured that we fully understand the challenge of managing this invasive species.
We asked Wendy some questions to find out more about this invasive species and its management.
Japanese knotweed is a serious ecological and structural threat.
This invasive species can:
- damage infrastructure – it can exploit small gaps in concrete, brickwork and other hardstanding if not appropriately managed, leading to further structural damage
- contribute to biodiversity loss – it will dominate habitats if left untreated, outcompeting native flora and reducing overall biodiversity
- impact the environment – it can destabilise river banks, leading to collapsed banks, which increases the sediment in waterways and the risk of flooding.
Japanese knotweed can be easy to misidentify for those who are inexperienced in identifying it. However, there are key characteristics to look out for.
- Flowering season: from July to August, Japanese knotweed is more easily identified because of its small, white flowers that grow in attractive clusters.
- Non-flowering seasons: outside the flowering period, identification requires more attention to detail. Its bamboo-like stems and heart-shaped alternate leaves are telltale signs, though there are hybrid species around with different shaped leaves, so this is not always the case. During winter and spring, the plant’s appearance changes significantly, making it harder to identify. In winter, it appears as dead, brown canes, while in spring, reddish-purple shoots emerge.
For those unfamiliar with Japanese knotweed, the best approach is to learn from experienced individuals through reading, field surveys and hands-on experience.
- Contain it: create a physical barrier around the plant to prevent people from inadvertently spreading it.
- Call a specialist: contact a certified professional who can advise on how to properly manage or eradicate the plant.
- Check your legal responsibility and be aware of your legal obligation to prevent the spread of Japanese knotweed to neighbouring land or the wild.
If you have concerns about Japanese knotweed, there are multiple benefits to engaging with a professional including:
- Cost efficiency: certified surveyors can provide quality assurance during Japanese knotweed excavations, ensuring no more soil is removed than necessary. They can recommend redistributing excavation materials within the site, reducing the need for costly landfill disposal.
- Environmental responsibility: by minimising waste disposal to landfill, certified professionals help clients adhere to sustainable practices.
- Comprehensive service: offering quality assurance as an additional service enhances client confidence, similar to the quality assurance processes used in bat surveys and other ecological assessments.
The Certified Surveyor in Japanese knotweed qualification is a vital tool in the ongoing effort to manage Japanese knotweed effectively. Congratulations, Wendy, on achieving this accreditation!