XLR8 is not my go to for killing crabgrass. I was using Tenacity which also works well but turns the crabgrass white and takes a while to kill them off. The white doesn't look great in the yard. XLR8 works faster and turns the crabgrass a dark green/brownish color that doesn't stand out badly, but they die off quickly and just go away and isn't noticeable like when using Tenacity. I have cool season grasses and it didn't harm them at all. This is my new go-to.