Hemp fabric really does biodegrade. Just over a year ago I added about 3 cups of undyed hemp canvas scraps to my compost bin (see my post Composting Hemp Fabric). Today I removed the entire year's worth of compost, ready to fertilize my garden, and found no trace of the bast fiber. Tip for composting hemp fabric: cut into small pieces no bigger than 1" x 3" and add to your bin when dry matter is needed.
