Call us for a free quote

01323 656 828 or 07736 690 888

Call us for a free quote

01323 656 828

 or

07736 690 888

JAPANESE KNOTWEED & INVASIVE PLANTS

Non-native and invasive plants are becoming a large problem in Britain, Japanese Knotweed alone is estimated to cost the UK economy £166 million a year!

Japanese Knotweed can grow upto 20cm per day and can grow through concrete and tarmac damaging buildings and foundations. Due to its prolific and destructive growth it’s a problem that is better treated promptly.

Japanese Knotweed – What Is It?

The Royal Horticultural Society say ‘Although rather attractive, Japanese knotweed (Fallopia japonica) is a real thug as it spreads rapidly. In winter the plant dies back beneath ground but by early summer the bamboo-like stems shoot to over 3-4m, suppressing all other growth. Eradication requires steely determination as it is very hard to remove by hand or with chemicals.’ Find out more about Japanese Knotweed on https://www.gov.uk/guidance/prevent-japanese-knotweed-from-spreading

Japanese Knotweed – Identification

SPRING

In early spring look out for red/purple shoots appearing through the ground which grow rapidly into canes, these too are characteristic in their red/purple colour.

SUMMER

By early summer the plants will be fully grown. Japanese knotweed has hollow stems with a distinctive purple speckle; stems can reach a maximum height of 3 to 4 metres in a growing season. Japanese knotweed grows very close together in dense patches with green heart shaped leaves.

LATE SUMMER/AUTUMN

Later in the summer, from around August to October, clusters of creamy white flowers appear on the plant. These provide a great source of nectar for insects, so look out for and influx of insects to your garden when identifying Japanese
knotweed in the summertime.

WINTER

As we move into winter, the leaves will fall from the plant and the canes will die. The canes turn brown and have a dark orange centre. The canes stay standing throughout the winter months, and can occasionally be seen amongst the new stands the following summer.

The invasive root system, combined with strong growth can damage foundations, buildings, roads, paving, retaining walls and architectural sites. It can grow up to 40mm per day- that is 1.2m per month! It can grow through concrete and tarmac and it spreads very rapidly.

The rhizome root system is very knotty and woody in appearance but if snapped it appears orange. This photograph shows an example of this. The depth of the roots can be up to 2m. However the spread is more as it can be as much as 7 metres in any direction from the parent plant.

Regeneration can occur from a piece of plant as small as 0.7g of root material or a 10mm length of root. The rhizome root material can remain dormant for up to 20 years.

Japanese Knotweed Removal – Our Services

  • Bespoke Japanese knotweed eradication plans
  • Japanese knotweed management plans
  • Full and reduced excavations
  • Membrane installations
  • Disposal of Japanese knotweed contaminated material via licensed haulier to an appropriate waste-management facility, with a full paper-trail supplied if required

Other Invasive Species

Giant Hogweed

Giant Hogweed is invasive and potentially harmful to people and pets. Chemicals in the sap can cause photodermititis or photosensitivity, where the skin becomes very sensitive to sunlight and may suffer blistering, pigmentation and long-lasting scars.