Tenacity herbicide (mesotrione) is from Syngenta and it will selectively control crabgrass, creeping bentgrass, nimblewill, and a number of broadleaf weeds in cool-season lawns. It is one of the most unique and effective herbicides that we have tested in a long time. Though it was labeled early in 2008 for golf course and sod farm use, the sports turf and residential and commercial lawn labels are unfortunately still on hold. Though it is always risky to predict when EPA will approve a product, it now looks like it will become available in December 2008. Stay tuned.