Fertilome Weed Free Zone Concentrate Mixes With Water To Apply With Your Pump Up Sprayer. Weed Free Zone is a post emergent herbicide containing carfentrazone and ester plus more. Kills a wide variety of weeds in a wider temperature range. While best results are in spring and fall when weeds are actively growing, Weed Free Zone will kill weeds in summer. Use with Spreader Sticker. May kill creeping charlie with one application. May seed two weeks after spraying with Weed Free Zone. May spray Weed Free Zone after two mowings of new grass seedings and four mowings of new sod. As with all broadleaf weed killers, do not spray on a windy day when you may spray drift on trees, shrubs or flowers. All broadleaf weed killers will kill anything with a broadleaf, weed or flower. 8 Oz. Concentrate.