Natural burlap is an alternative to synthetic weed fabric. It prevents weed seeds from coming into contact with the soil where they can germinate, but its high permeability allows water to penetrate easily. Gardeners can lay yards of burlap across the garden bed and cut slits through the cloth to place plants in the soil. Cover the burlap with a thin layer of mulch. Burlap measures 4 feet x 2 feet.