Barley Barley Crop Icon Brassicas Brassicas Crop Icon Sugar Beet Sugar Beet Carrots Carrots Icon Leeks Leek Icon Maize Maize Icon Oilseed Oilseed Icon Onions Onions Icon Other Cereals Other Cereals Icon O R T Peas And Beans Peas and beans Icon Potatoes Potatoes Icon Salad Crops Salad Crops Icon Soft Fruits Crops Soft Fruits Icon Top Fruits Crops Top Fruits Icon Wheat Crops Wheat Icon Calendar Calendar icon Arrow Next Arrow Previous Close Checkmark


False oat-grass is very common in grassland and in hedgerows throughout the British Isles. The onion couch variant is a more localised problem, generally in loams of more open texture. Once present it is very difficult to totally eradicate as each root nodule can develop into a new plant and they are very resistant to dry conditions.


Very tall perennial 60-150 cm. Swollen bulbous nodules at the stem-base indicate the onion couch variety of false oat-grass. Panicle is like miniature wild oat head but more upright condensed and narrow.


Onion couch ligule Short to medium: up to 3 mm.










Auricles: Absent

Leaf blade: Long, narrow, rough and sparsely hairy above, or hairless.

Onion couch 1
Onion couch 2
Onion couch ligule photo Onion couch/False oat-grass ligule. Photo © HGCA.
Onion couch 3 Onion couch with distinctive swollen bulbous nodules at base of stems. Photo © Blackthorn Arable.



Onion couch - mature Onion couch/False oat-grass flower heads. Photo © Nigel Caittlin/Alamy.

Identify grass-weeds

You can use this page to help identify the grass-weeds in your crops, and then find out about the best crop protection products to control them.

View now