A sheet of black plastic should be laid over the surface to retain moisture. While there are several methods of harvesting compost and adding new bedding, the most convenient is to move the compost to one side of the bin and add new bedding and garbage to the other. Replacing the plastic sheet on only the half of the bin containing the new bedding will allow the compost to dry out some. The worms will migrate to the fresh material and the compost may be removed and replaced with new bedding. This migration may take several weeks.
Growers know castings to be the most nutrient-dense compost available.
Castings promote soil structure and fertility, while offering plants an excellent source of non-burning, readily available nitrogen To maintain this system simply rotate burial of food wastes throughout the bin. Every 3-6 months compost should be moved to one side of the bin and new bedding added to the empty half. At this time start burying wastes in the new bedding only. Within one month worms will populate the new bedding, finished compost may be harvested and the rest of the bin can be rebedded. During the winter, worm bins should be kept in a cool indoor space such as a basement or warm garage to avoid freezing.