Managing invasive, injurious and harmful plants

Ground Control's guide to harmful weeds

Like all of us in our own gardens at this time of year, our landscaping partners, Ground Control are battling weeds in their planting areas. Where those weeds are harmful, invasive or injurious, it’s the team’s obligation – legally and for the good of the environment – to tackle them.

A weed is defined by Britannica Dictionary as a ‘a plant that grows very quickly where it is not wanted and covers or kills more desirable plants’.  The secondary but also important attribute is that of a plant that causes harm, either to humans, livestock, property, infrastructure or the wider environment.

On an infrastructure project like the Hinkley Connection Project, these are the most common weeds to look out for and report to your environmental manager or ecologist:

Invasive species – defined by DEFRA as those brought into the UK that have the ability to spread, causing damage to the environment, our health and the way we live. Invasive non-native species are now widely recognised as the second biggest threat to biodiversity worldwide.

There are 32 species listed on the DEFRA website. Those that are widely spread in the UK include Giant Hogweed, which can cause harm to human health, Himalyan balsam, floating pennywort and Japanese knotweed, which has been identified on the project during Ground Control’s works.

Legally, landowners must not: import, keep, breed, transport, sell, grow, cultivate or permit these species to reproduce.

Japanese Knotweed is an extremely invasive plant that thrives on disturbance. The tiniest piece can re-grow, spread and damage concrete, tarmac, flood-defences and the stability of river banks and outcompete native flora.  Despite its fearsome reputation and legal powers that DEFRA can take against the owners of private land where Japanese Knotweed is invading neighbouring properties, it is just another weed that can be managed through a range of techniques offered by approved contractors like Ground Control.

Injurious weeds  –  native species, which have been deemed to cause a problem to farming productivity by effecting arable land, pasture and livestock. The five species of injurious weed classified under the Weeds Act 1959 are: Common ragwort, Spear thistle, Creeping or field thistle, Curled dock and Broadleaved dock.

As with invasive weeds it is not an offence to have injurious weeds growing on your land, but they must not be allowed to spread to neighbouring agricultural land. If these species are not prevented from spreading an enforcement notice can be issued.

Harmful weeds – The Royal Horticultural Society Lists over 100 garden and house plant species that are potentially harmful to people, with effects ranging from skin and eye irritation to poisoning. These include hemlock which has been identified on the Hinkley Connection route.

When Ground Control encounters weeds within the planting areas that could cause harm, we record the location, inform the landowner and National Grid and develop a management plan to treat the plants. These are species specific but generally a series of herbicide applications and monitoring, coordinated during the growing season from March to October.

Ragwort, dock and thistle

Himalayan Balsam

Japanese Knotweed

What to do in case of accidental poisoning:

The symptoms to looks out for:

  • being sick
  • stomach pains
  • confusion
  • drowsiness and fainting fits

If a child suddenly develops these symptoms, they may have been poisoned, particularly if they’re also drowsy and confused.

The NHS advice is clear: do not try and treat them yourself.  Seek medical advice immediately from a hospital accident and emergency department. Do not panic and do not try to make the person sick. Take a sample of the plant with you – as many parts of the plant as you can for accurate identification e.g. leaves, flowers, fruits, stem.

If you suspect a weed found on site to be invasive, injurious or harmful,  contact your environmental manager or ecology team.