We have had less than satisfactory results on grass with Ignite, too, some are harder to kill than others. Another thing I noticed with my cotton that I sprayed over the top with Ignite is that it didn't kill the Velvetleaf. I sprayed some over the top and then came back with a second shot a few weeks later under the hoods. The second time under the hoods seems to have finished it off as there is none in the middles. The Valor I added may have heated it up enough to get it that time. But the Velvetleaf in the row that only got sprayed once was burned back to a few inches above the ground. Then it took off again and in many cases forked into two main stems. Looks like two plants until you get in there under the canopy to hook it and find its just one root system with two stalks. As far as FirstRate and marestail, I have had much better results with Ignite and marestail than I have FirstRate. Although to me, this seems like the two different modes of action would be very antagonistic, I know of several around here that have tank mixed Ignite and Glypho and claim to have gotten excellent results. But understand I am talking burn-down, not spraying over the top. Wonder what Clethodim would do for your grasses tank mixed with Ignite?