Go natural with Biobag 33 Gallon Lawn and Leaf Bag (12/5 count). BioBag Lawn and Leaf bags can be set at curbside for up to 12 days before the collected waste will begin to break the bag down. We strongly recommend that wet grass clippings be left on the lawn, where the clippings will quickly biodegrade and add nutrient value to your lawn. Placing wet grass clippings in either a paper bag or a BioBag can stimulate bag decomposition within three or four days. .