This is the best form of post emergent crabgrass control on the market today. Hands down this stuff works great you must follow directions but its simple to do. Quinclorac must be used with methylated seed oil. This is a surfactant that makes the product go into the weed efficiently. I have tried dish soaps but there is a huge difference when use a methylated seed oil. Remember to read the entire label before you use it. Use the link HERE to get the full Label and here for the MSDS sheet.
When controlling crabgrass remember that it loves the hot weather and when you get those rain showers in July that do nothing for your turf crabgrass will grow like crazy. So your window of opportunity will p[ass quickly because the crabgrass plant is to mature at this point no selective products work.