Before you go to all the effort to control crab grass, consider whether you can learn to coexist. Crab grass is, after all, grass in a lawn full of, well, grass. And a lawn doesn’t have to be ...

One reviewer noted that Preen isn't a crabgrass killer but a preventer. The implication is that this product, even as a sometimes post-emergent treatment, isn't meant to deal with a lawn full of ...