NC State Extension

Earthworms and Worm Bins

Vermicomposting is increasing in popularity in households, schools, and businesses. It is easy and inexpensive to set up worm bins in any of those settings. Worm bins can be located inside or outdoors, as a properly maintained bin does not produce odors. If setting up the bin outdoors, be sure you can maintain temperatures of 55 – 80 degrees F (13 – 27 C) year-round.


About vermicomposting earthworms…

worm pooMore than 9,000 species of earthworms have been identified, yet only seven species are suitable for vermicomposting. Of the seven species, only one is typically used in North America: Eisenia fetida (one common name is red wiggler). It is very important that this species of earthworm is used for vermicomposting, so do not pick up earthworms in the environment and put them in your worm bin. Instead, purchase Eisenia fetida from a worm grower.


About worm bins…

Worm bins may be purchased from commercial manufacturers (like the ones in the photo below) or constructed from wood or plastic storage bins. They can also be created using concrete blocks or other building materials. Your earthworms need to be shielded from light and rain, so be sure to cover the bin with something: a lid, burlap sacks, cardboard, loose plastic, plywood, etc. Make sure that oxygen can flow into the bin (e.g., drill air holes). There should also be some way to drain excess liquid from the bin (drill holes in the bottom). Note: If you’re vermicomposting correctly, excess liquid will not accumulate in the bin.

six worm bins

Photo showing six different types of worm bins.


Where to keep a worm bin…

Worm bins can be kept indoors or outdoors in the shade. The ideal temperature for composting earthworms is 55 – 80 degrees F (13 – 27 C). Your earthworms will survive at 32 – 95 degrees F (0 – 35 C) if they have at least 4 inches of bedding and you insulate the bin during colder months. You can insulate your worm bin with blankets, straw, blue board or other material to keep it warm.


Resources

  • Vermicomposting & Earthworm Q&A (Rhonda Sherman, Vermicomposting News – 2013). Simple questions and answers about vermicomposting and earthworms.
  • Worm Bin Troubleshooting (Rhonda Sherman, Vermicomposting News – 7/09). Tips for taking care of your worm bin.
  • Worms Can Recycle Your Garbage (Rhonda Sherman, AG-473-18, 2012 revised, North Carolina Cooperative Extension). How to set up and maintain a worm bin in your home or office to compost food scraps.