Pulverize Weed Killer for Lawns uses the active ingredient iron to selectively control and suppress broadleaf weeds growing in lawns. Thoroughly spray this product on weeds using a coarse nozzle setting to reduce drift. Repeat treatments in three to four weeks for best results. Dying weeds will be seen within hours of application. Treated weeds， moss or algae will turn brown or black. Occasionally a darkening of grass leaf blades can occur after treatment however， the grass will recover within a few days to weeks.Find the WEED KILLER 32OZ at Ace.