Preen Mulch with Extended Control Weed Preventer is the only landscape mulch that comes with added Preen weed preventers already mixed in. In one easy step, apply mulch and block weeds for up to 6 months. While it is recommended to spread ordinary mulches 3 in. deep, Preen Mulch with Extended Control Weed Preventer can be spread only 2 in. deep because of its additional built-in Preen weed barrier. This means that each bag covers 12 sq. ft. of ground. That’s 30% more ground coverage than ordinary mulches - while also providing effective, long-lasting control of broadleaf and grassy weeds. Preen Black Hardwood Mulch 2 cu ft