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 2 In. to 3 In. of bark mulch. Made of ultra violet-treated polyethylene. 6-year product is 1.2 Oz. per square yard (or 1.6 milliliter).