Invasive non-native plants - Giant Hogweed and Japanese Knotweed

Japanese Knotweed and Giant Hogweed are non-native plants and are highly invasive as they have no natural enemies to control them in the United Kingdom. As a result, they out compete native plants leading to large groups of plants that grow very tall.  Read on to: 

  • find out how to identify these plants; and
  • what to do if you find them on private or public land.   

Quick links

About Giant Hogweed

Giant Hogweed is a fast-growing invasive plant that mainly grows next to water, in damp meadows or on derelict land.

  • The sap from Giant Hogweed can cause serious painful burns to humans and animals and make skin sensitive to strong sunlight.
  • Keep away from the plants to avoid the risk of injury and do not touch them.  
  • If you do come into contact with the sap wash the area thoroughly, keep out of direct sunlight and seek medical attention.

Identifying Giant Hogweed

Giant hogweed Giant hogweed is a tall, cow parsley-like plant with thick bristly stems that are often purple-blotched. It can reach a height of 13 feet/4 meters.

The flowers are white and held in umbels facing upwards about 50 centimetres in diameter (flat-topped clusters, like those of carrots or cow parsley).

Giant Hogweed on private land

It is not illegal to have Giant Hogweed growing on your land, but it is an offence to cause or allow it to spread. Control of this plant is the responsibility of the landowner.

  • You must not remove or dispose of Giant Hogweed as it could cause the plant to spread which is an offence.
  • You must not dispose of Giant hogweed in your brown recycling bin or take it to a household waste and recycling centre as this is an offence - it must be disposed of as controlled waste.

If you see Giant Hogweed on private land, eg a neighbouring property, a construction site or agricultural fields, speak to the land owner in the first instance.

  • To find out who owns a piece of land search the HM Land Registry

Search for property information from HM Land Registry - GOV.UK (www.gov.uk)

Giant Hogweed on public land

We make every effort to contain the spread of giant Hogweed on public land.

If you find Giant Hogweed on public land within the Borough of Bury, report it to us.


Report a sighting of Giant Hogweed on public land

About Japanese Knotweed

Japanese Knotweed is a highly invasive weed which overwhelms other plants.  It spreads rapidly (up to 10 cm per day) and can reach a height of 10 feet (3 meters).  It can:

  • grow almost anywhere
  • cause structural damage to buildings and other structures (eg by growing through cracks in masonry)
  • reduce land values
  • cause difficulty in obtaining a mortgage

Identifying Japanese Knotweed

Japanese knotweed Look for:

  • Green shovel shaped leaves
  • Bamboo-like stems
  • Small white flowers (September to October)

Japanese Knotweed on private land

It is not illegal to have Japanese Knotweed growing on your land, but it is an offence to cause or allow it to spread. Control of the plants is the responsibility of the landowner.

  • You must not remove or dispose of Japanese Knotweed as it could cause the plant to spread which is an offence.
  • You must not dispose of Japanese Knotweed in your brown recycling bin or take it to a household waste and recycling centre as this is an offence - it must be disposed of as controlled waste.

If you see Japanese Knotweed on private land, eg a neighbouring property, a construction site or agricultural fields, speak to the land owner in the first instance.

  • To find out who owns a piece of land search the HM Land Registry

Search for property information from HM Land Registry - GOV.UK (www.gov.uk)

Japanese Knotweed on public land

We make every effort to contain the spread of Japanese Knotweed on public land.

If you find Japanese Knotweed on public land within the Borough of Bury, report it to us.

Report a sighting of Japanese Knotweed on public land


Other non-native plants

The Non-native Species Secretariat (NNSS) has responsibility for helping to co-ordinate the approach to invasive non-native species in Great Britain.

If you are interested in finding our more about other invasive non-native species, check the NNSS website where you can look up information about specific species and learn how to identify them.