IRON X! Selective Weed Killer for Lawns Naturally controls broadleaf weeds including dandelions, English daisy, white clover and more. Selective weed killer suppresses weeds quickly without harming your lawn. Within hours of application, dying weeds turn black or brown. Works even in cold weather and on new lawns; people and pets can enter as soon as spray dries. 16-ounce concentrate makes 3.125 gallons.