Couch Grass
Grassy weed
Couch grass is a persistent perennial grass that spreads through borders, lawns and vegetable plots by vigorous underground rhizomes. It is much harder to remove than annual weeds because even a short piece of root can grow again. Steady, repeated physical control is needed, especially before it becomes woven through established plants.
How to identify it
Couch grass forms rough, upright leafy shoots 30 to 120 cm tall and narrow, flat grey-green leaves about 3 to 10 mm wide. Its flower spike is slender, with small spikelets attached alternately along the stem. The key feature is the network of tough, white to cream underground rhizomes, often with sharp pointed tips, which travel horizontally through the soil. Rhizomes produce new shoots at intervals and can extend well beyond the visible clump. Fibrous roots emerge from these rhizomes.
Where it grows
It is common throughout the UK in gardens, allotments, lawns, rough ground and neglected boundaries. Growth is strongest from spring to autumn, but underground rhizomes survive winter and regrow when conditions improve. It readily invades cultivated ground, compost-enriched beds and lawn edges, particularly where soil has been disturbed or rhizomes have been moved with soil.
Why it is a problem
Couch grass competes strongly for water, nutrients and space, and its rhizomes thread through crop roots, herbaceous borders and strawberry beds. Every fragment left in the soil can regrow, so hurried digging often spreads rather than solves the problem. Dense growth also makes cultivation difficult and can rapidly reclaim cleared ground.
How to control it
Dig clumps out carefully with a fork, tracing and removing every scrap of white rhizome, including pieces running beneath neighbouring plants. Repeat this work whenever new shoots appear, as persistence gradually exhausts the remaining rhizomes. Never rotavate couch grass, because chopping rhizomes spreads it into many new plants. Cover cleared areas with a secure light-excluding cover for an extended period, and mulch beds after removal. Check imported soil, compost and lawn edges for fresh rhizome fragments.
Commonly confused with
It is confused with other coarse grasses, including perennial ryegrass and false oat-grass. Couch grass is most reliably identified by its tough white, sharp-tipped underground rhizomes and its slender spike. Perennial ryegrass forms clumps rather than an extensive network of travelling rhizomes.
Couch Grass: frequently asked questions
How do I identify couch grass?
Couch grass forms rough, upright leafy shoots 30 to 120 cm tall and narrow, flat grey-green leaves about 3 to 10 mm wide.
How do I get rid of couch grass?
Dig clumps out carefully with a fork, tracing and removing every scrap of white rhizome, including pieces running beneath neighbouring plants.
Where does couch grass grow?
It is common throughout the UK in gardens, allotments, lawns, rough ground and neglected boundaries.
General guidance for UK gardens and allotments, focused on prevention and non-chemical control. For a confirmed identification, the RHS or a local garden centre can help. Page updated 18 Sep 2026.