I sprayed my clover plots in late May and have been very happy with the results. I found a great deal on some Raptor a couple of years ago, which is supposed to kill both grasses and broadleafs, but not harm clover, chicory, or alfalfa. I've never had that good of results with it, but probably need to do a better job of adding ammonium sulfate and surfactant. To the Raptor mix this spring, I also added Select 2EC (clethodim) and crop oil. Clethodim is grass selective. I had one plot that was terrible with grass. The grass was already knee high and shading out my clover. No more! That plot is the cleanest now that it has ever been. After last summer's experience, I'll pay a little more and spray Clethodim and Raptor. After the Raptor is used up, I'll be looking for 2-4-db to take care of the broadleaf problems.