Knowledge Hub Article

Couch - Occurrence

In the UK, there are five main species of perennial grass weeds of arable crops that are commonly known as Couch or Twitch.  

 

Common Couch (Elymus repens)

Elytrigia or Agropyron repens 

Very common throughout England and Wales, more scattered in Scotland.  Very common in a wide range of habitats, including field margins, hedgerows and rough grassland as well as arable fields.  Up until the mid-1970s this was the most important weed of arable crops in the UK.

Couch - Common

 Distribution of common couch based on 10 x 10 km grid records in the Atlas of the British Flora (2002).

Source: The New Atlas of the British and Irish Flora. C. D. Preston, D.A. Pearman and T.D. Dines, 2002 (Oxford University Press)

 

 

Black Bent (Agrostis gigantea)

Widespread in England, but mainly on lighter soils than common couch.  Probably under-recorded.

Couch - Black Bent

Source: The New Atlas of the British and Irish Flora. C. D. Preston, D.A. Pearman and T.D. Dines, 2002 (Oxford University Press)

 

Creeping Bent (Agrostis stolonifera)

Very common throughout the UK in a very wide range  of habitats but less of a problem as an arable weed than common couch. 

Couch - Creeping Bent

Source: The New Atlas of the British and Irish Flora. C. D. Preston, D.A. Pearman and T.D. Dines, 2002 (Oxford University Press)

 

Onion Couch (Arrhenatherum elatius var. bulbosum)

A variant of false oat-grass which is abundant throughout the UK in field margins, hedgerows, rough grassland and waste ground.  The onion couch form has a much more restricted distribution as an arable weed, being largely confined to southern and central England.

Couch - False Oat-grass

Source: The New Atlas of the British and Irish Flora. C. D. Preston, D.A. Pearman and T.D. Dines, 2002 (Oxford University Press)

 

Creeping Soft-grass (Holcus mollis)

Widely distributed throughout the UK and occasionally a weed of arable land, usually on lighter, acidic soils.

Couch - Creeping soft-grass

Source: The New Atlas of the British and Irish Flora. C. D. Preston, D.A. Pearman and T.D. Dines, 2002 (Oxford University Press)