After a rainstorm, while the ground is still humid, you may have noticed worms coming to the surface and leaving behind dark droppings. Worm sewage, commonly called worm castings, makes high quality, nutrient rich compost. Compared to regular soil, vermicompost, the compost from worm sewage, is five times higher in nitrogen, seven times higher in phosphorus and has eleven times as much potassium. If you want to compost worm castings, you can either buy a pre-fabricated wormery or make your own using a shallow bin.
Check the wormery bedding every time you add kitchen scraps. When you notice that most of the bedding and scraps have turned into a dark, rich loam, it it time to harvest the vermicompost.
Spread the newspaper over the floor or ground where you are going to work. Scoop out the vermicompost with the spade or your hands, placing it on one side of the newspaper.
Shine a bright light on the compost pile. Worms do not like light and will wriggle down into the compost to hide.
Brush off the top layer of compost with your hands onto another piece of newspaper or a tray. Repeat the process as the worm burrow down to hide from the light again.
Return the worms to the wormery. Add more bedding as necessary. Repeat the process every three months or so.
Use the vermicompost as mulch, adding 1or 2 inches around your plants. You can also mix it directly into potting soil to enrich it.