Use Ortho WeedClear Weed Killer for Lawns Concentrate to kill over 250 listed weeds including dandelion and clover down to the root, without harming your lawn (when used as directed)This weed control product is rainproof in 1 hour and produces results in just 1 applicationUse to kill weeds in turfgrasses including St. Augustinegrass (not Floratam), Bermudagrass, Centipedegrass, Zoysiagrass, Buffalograss, and Bahiagrass, Kentucky Bluegrass, Ryegrass, Tall Fescue, and Fine FescueApply this lawn weed killer concentrate using a tank sprayer or Ortho Dial N Spray hose-end sprayer to small, actively growing weeds when daytime temperatures are below 90°FThis 1 gal. container of Ortho WeedClear Weed Killer for Lawns Concentrate treats up to 64,000 sq. ft.