Weeds: Couch Grass

Couch grass (also known as quick, quitch, cooch and witchgrass) is a very common perennial weed. This grass forms large seed heads which are a good source of food for many native birds, but within a flower garden or vegetable patch it can be very invasive.

Couch is able to reproduce from white rhizomes (roots) that form a network under the ground. This is the way to identify this weed from less bothersome annual or perennial grass species. In short, if the root system of the grass is very thin and fibrous it isn’t couch!

Along the rhizome (root) are nodules where the leaves will develop. This is a very clever adaptation because it means that if the rhizome is broken or damaged every little piece can sprout. If you chop up these rhizomes you will multipy your couch problem.

How to manage couch grass:

1. Dig the roots (rhizomes) out – carefully. Use a fork and try to keep the root system in tact.
2. Do not rotavate – you will just create more plants!
3. Mulch aka ‘no dig’ and then trowl or pull out roots. Don’t be fooled to think that cardboard and a thick composted mulch will completely stop couch grass coming through – it is very persistent. However, it will be weakened and, most importantly, a nice soft layer of mulch means it is easier to pull out roots intact.
4. Weedkillers (herbicides) will kill couch grass if you are happy to take this route, but it will take a few applications over a number of weeks.

Couch is a weed you will want to deal with as effectively as possible. It out competes most crops, grows quickly and becomes entangled in the roots of any perenial plants.