Couch, also known as witchgrass, is a common perennial species of grass native to most of Europe, Asia, the Arctic biome, and northwest Africa. It has been brought into other mild climates for forage or erosion control but is often considered a weed.
The soils were couch is common, often have adequate bacterial activity but not enough humus. Soil may also lack Calcium but have high Magnesium concentration.
The foliage of couch is an important forage grass for many grazing mammals. The seeds are eaten by several species of grassland birds, particularly buntings and finches.