Vermicompost is compost enhanced by the presence and natural activity of earthworms. The vermicompost is generated by the earthworms through their natural digestive processes. The process is called vermicomposting and the end result is called vermicast or worm castings, which is rich in nutrients and makes for a great organic fertilizer for your back yard garden.
Vermicomposting uses primarily two species of worms; Red Earthworms or Red Wigglers. These worms are not the typical worms found in soil but are specialized for breaking down vegetable and plant matter. Essentially the earthworms eat the food waste and organic waste and excrete it as rich worm castings. The combination of these worm castings and partially decomposed organic matter is vermicompost.
Managing a worm farm to create vermicompost is inexpensive and great for the environment but is very different than managing an organic digester. A worm farm is much more labor intensive as the worms require special conditions to survive or thrive. A worm farm requires management of airflow, humidity and temperature while an organic digester is essentially worry and maintenance free. However, as with all composting, vermicomposting results in a fertilizer, you can use in your gardens while an organic digester does not.