Filter fabric is designed to trap dirt in the box while allowing excess water to drip out through the bottom drain holes of the window box. It prevents drain holes from clogging over time and allows for much more filtered, cleaner water coming out the bottom of the box. Our filter fabric rolls are designed to fit inside our standard and XL window boxes. Simply cut 2-3" longer than the length of the inside of the window box and lay on the bottom. Cover with soil and begin planting. If you are using our self-watering reservoirs then place underneath the reservoir.
Dimensions: 36 feet long x 9" wide