Woven weed mats are expensive if used on large areas, but are worth the cost for long-term weed control. They allow air and water to penetrate soil. Roofing paper is durable and long lasting. It works well under gravel on driveways and along fencelines. Use 80-pound grade for durability.
Black plastic is one of the least desirable mulches.
It breaks down in one season and shoots of many stronger perennial weeds will break through it. Desirable plants will have weak root systems under plastic mulches and slugs and diseases can be problems. Pests of the Garden and Small Farm. University of California. Oakland, CA 94608- 1239.