Weed control fabric blocks out light that most weeds need to survive and grow. It's easy to install, removable and reusable. Weed control fabric lets moisture and air into the soil. Our Turbo-Tomato! Tomato Weed Barrier and Mulch is made of food-grade plastic and warms the soil as well as controlling weeds. Because water doesn't pass through the plastic, a watering system is needed.