Weeds - Grass Weeds Information and Photo Gallery

Couch grass

Weeds_couch.jpg (6389 bytes)

Appearance

Couch grass (Agropyron repens) is sometimes known as Twitch and is a very vigorous perennial grass with creeping underground stems. These are white, straight and closely resemble roots going very deep on cultivated land and growing as much as two metres in a single season when conditions are favourable. It tends to occur as clumps of stems which spiky shoots. It grows taller and broader than lawn grass, up to 120 cm. The leaves are narrow and flat with a bluish tinge up to 5 mm wide. They are also hairy on the inner surface and rough at the edges.

Occurrence and spread

Couch grass is one of the worst perennial weeds and is very widespread throughout the UK although it is rarely found in the Highlands of Scotland. It thrives in any type of soil.

New aerial shoots emerge in autumn and spring rising from tips of the underground creeping stems and from small buds distributed along their length. These buds remain dormant when the tip is growing strong but if growth is interrupted or the above ground stem damaged by cultivation these buds can rapidly produce new aerial shoots. The leafy new shoots then generate new underground stems with more bulbs. Flowers are occasionally produced but seeds are unlikely to germinate except in neglected areas. Seed production is also quite low with each flower spike generating around 50 seeds each. Couch rarely flowers in the autumn months.

Control and management

Couch is one of the most difficult weeds to control on cultivated fields. Best control will be achieved by herbicides such as glyphosate applied when the grass is actively growing. This can be difficult near and around crops post-emergence. Seek advice from your BASIS qualified adviser.

ADLib logo Content provided by the Agricultural Document Library
© University of Hertfordshire, 2011