Give us an idea of how much you have and where is it located. Is it in a lawn if so what type. If you do a search there are several universities that give suggestions. If you have tried those products please tell us. Perhaps someone will know when the application is most effective.

I too have a Green Kyllinga problem. It's in an Argentinian Bahia lawn. I re-sodded the lawn last summer. It was gorgeous a month after I re-sodded, but this year it came up with a billion weeds.

I used Momentum to kill all the weeds and it worked fine, but now I am left with Green Kyllinga, the crappy Bermuda Grass ( that is considered a weed down here) and some crabgrass.

I heard that using baking (soda , powder?) to kill the remaining crabgrass. Anyone know any details? I also read that a 20% vinegar would kill the Bermuda, but will it also kill the Bahia?

And any help with the Green Kyllinga (a sedge grass) would be helpful. I know two products, Certainty, and Sedgehammer that work to some degree, but they are super expensive, and I would like to stay natural if I can.