What is this grass, and how do I get rid of it?
It grows at an alarming rate, and is taking over the garden.
Certified GKH Gardening Expert
That will be very hard to say without seeing seed heads, or other identifying factors. It will also be important to note that the grasses that are invasive in your country may be different than here in the US.
Try contacting your local agricultural agency and they will be able to better help you.