Alliance Gator NGF20-0405000 4' x 50' Gator GF20 Polyspun Fabric - Gator GF20 is an excellent geotextile that protects against the growth of weeds. It is specially formulated to resist deterioration due to exposure to ultraviolet light and is inert to commonly encountered soil chemicals. This fabric will not rot or mildew and is non-biodegradable. It allows water, fertilizer and air to pass through.