AGU Weed Barrier AG4300 is an easy-to-use, environmentally safe fabric that controls weeds before they start. Its unique design provides several advantages over conventional weed barrier products. Excellent for Long-Term Landscapes. The fabrics’ higher carbon black content provides superior light-blocking capabilities to protect against the toughest perennial weeds. The design also prevents unraveling and makes the material easier to cut. In addition, AGU Weed Barrier AG4300 is hydrophilic treated, providing improved water and nutrient flow through the fabric.