Ortho Weed B Gon Plus Crabgrass Control kills crabgrass, dandelions and other common lawn weeds. Kills over 200 weeds to the roots. Won't harm the lawn - guaranteed (when used as directed). Starts working immediately. Coverage: spot treatment. Active ingredients: 0.313% 2,4-Dimethylamine Salt, 0.104% Quinclorac, 0.029% Dicamba.