I've heard of using regular corn meal around roses as a fungus preventitive.
If it doesnt kill grass as long as you keep it away from the canes I suppose it should be okay.
Let us know how it works on weeds!

Whats a pre-emergent anyways? does it kill weeds before they sprout?

Hi, here's a link a FAQ about using it as a pre-emergent. If it would help control foxtail and cheat grass, I'd be very happy. If it would also help with wild geranium and bine weed, I'd be ecstatic! :-)

I am going to apply it around my roses when I give them their tea this week.

Cheers,
Michelle

Here is a link that might be useful: corn gluten meal for weed control