Mow it off, if it grows tall, let it get so tall until it tries to bloom than mow it off again. When it tries to bloom it has to be a lot of energy into it, so if it is mowed it takes more and more out of the plant to grow, to bloom again. Grass deals with being mowed a lot better than a lot of weeds.
Or get someone to fence it off for goats for a while to eat it all down, they'll probably kill all off for you and the grass would grow back nicely. I don't know about where you live but lots of people here rent large fields for cows and other livestock, and offend fence it off for themselves. Plus it fertilizes your field.
Last edited by Cruiser; 06-11-2012 at 08:24 AM.