DeWitt Weed-Barrier is ideal for permanent landscape areas, flower beds, shrubs and trees to control weeds. Allows water, air and nutrients to pass freely to soil while blocking sunlight. Will last for years in direct sunlight, but more appealing under 2in to 3in of bark mulch. Made of ultra violet-treated Pointbond Polypropylene 15 year product is 1.5 oz. per square yard.