Ready-made worm bins such as the Worm Factory, the VermiHut, or the Worm Farm Composter are available for purchase. You can also make a worm bin out of one or more plastic tubs or buckets. The instructions below describe one method, and there are lots of other examples available online. Get creative with the materials you have on hand! Be sure your bin has ventilation and a way of preventing buildup of excess liquid.
The worm bin should be opaque, because worms do not like to be exposed to light. A worm bin made of one container set inside another can make harvesting the worm castings easier if you add food to only one bin at a time. The worms will migrate towards the food source and leave their castings behind.
- One or two plastic containers with a lid. An opaque plastic storage tub works well. Each container should have a volume of at least one cubic foot.
- Drill with quarter-inch (or similar size) bit
- Newspaper, clean cardboard, used paper towels (chemical-free), or paper egg cartons for bedding
- Fine screen to keep out pests & glue (optional)
- Tray (optional)
- Drill several holes in the lid of one container. If using a quarter inch bit, drill 8 to 10 holes (more if using a smaller bit, fewer if using a larger bit).
- Drill several holes in the sides of the container (both containers if using two) at about an inch or two below the rim of the bin.
- Create a system for drainage. If you are using one container, you can drill several holes in the bottom of and use a tray to catch liquid that comes out. If you are using two containers, you can drill several holes in the bottom of both containers and use one of the lids as a tray to catch liquid from the bottom. Or, you can drill several holes in the bottom of one container and leave the bottom of the other container intact. The container with holes in the bottom will be placed inside the container without holes in the bottom.
- Glue screen over holes (optional). If desired, attach fine screen over the holes you drilled to help prevent fruit flies or other small invertebrates from entering. See below for other ways to prevent or control pests.
- Make bedding and add worms. Use a shredder or your hands to finely shred or tear the newspaper, cardboard, or paper towels into one-inch pieces or narrow strips to use as bedding. Moisten the bedding by misting it thoroughly with water or soaking it in water and squeezing out the excess. The bedding should be about as moist as a wrung-out sponge. Fill the bin (both layers if using two containers) about two-thirds full of bedding and gently add the worms on top of the bedding. They will burrow down by themselves. Now you're ready to feed your worms!