CO-Horts Blog

Tuesday, February 25, 2020

The Adventures in Vermicomposting

Posted By: Lisa Mason, Arapahoe County Extension

The start of a new year also means it is time to plan the 2020 gardening season! If you are ready to get started now in the cold, winter months, consider starting a vermicomposting bin!
Vermicomposting is a method of composting using worms that offers a variety of benefits, including reducing landfill waste and having nutrient and microbe-rich compost to add to our gardens and house plants.
According to North Carolina State University Extension, “in 2006, the U.S. EPA estimated that 55-65% of the waste generated in the United States is residential. Most of what we throw away is organic materials that could be vermicomposted, composted, or recycled. Paper and paperboard products account for 34%, and food scraps and yard trimmings make up 25% (by weight).”
Vermicomposting is a fun way to reduce waste in your home. Since the worms need to stay between 59 – 77 degrees Fahrenheit, most people that live in cold winter climates choose to have their worm bin inside the house, including the kitchen or basement. Having the bin in the house provides easy access to feed the worms. If the bin is functioning correctly, it will be low maintenance and not emit any negative odors.
Red wigglers just added to the worm bin. Photo: Lisa Mason
My husband and I started our first worm bin in November.  So far the process has been a little trial and error to get the right conditions in the bin. Now that we have the conditions right, the bin has been very low maintenance. We have thoroughly enjoyed watching the worms in their ecosystem.
There are a variety of bin options available to purchase. You can even make your own bins with tutorials found online. If you choose to make your own bin, be sure it has adequate air circulation. Some bins have a spout to collect the liquid from the base of the bin which is a nutrient-rich compost tea. We chose a bin that is made of beetle-kill pine made locally in Colorado. We chose that bin because we like to shop local and beetle-kill wood products support Colorado’s forest health. The wood bins also offer nice air circulation. The only challenge we had with a wood bin is maintaining enough moisture inside the bid. We routinely add some water to make sure the bedding stays moist for the worms.  
Our new worm bin! We can have up to 5 layers, but right now we started with one. Photo: Lisa Mason 
 Here are a few tips for getting started:
  • The materials you need include: a bin that contains moisture and provides darkness for worms, bedding, water, worms, and kitchen scraps.
  • Kitchen scraps can include fruits, vegetables, coffee grounds and filters, tea bags, finely crushed egg shells, etc. Cut up kitchen scraps for faster composting.
  • Foods to avoid adding to your worm bin include dairy, meat and citrus.
  • Bedding provides the worms a place to live. You can use shredded newspaper (black ink only) and shredded cardboard.
  • Keep the bedding moist. All bedding should be as wet as a wrung-out sponge.
  • Red wigglers (Eisenia foetida) are the best worms to use for vermicomposting. They can be ordered along or purchased at some local garden stores and bait stores.
  • Add kitchen scraps slowly. If you add too much food too quickly, the bin may start to smell or attract pests like fruit flies. Cover all food with more bedding to bury it. As the worm bin becomes more established, you can increase the amount of food in the bin. 

The wet bedding provides a home for the worms. Photo: Lisa Mason
After several months, you will have nutrient rich compost! According to the University of Nebraska Extension, “compared to ordinary soil, the worm castings contain five times more nitrogen, seven times more phosphorus and 11 times more potassium. They are rich in humic acids and improve the structure of the soil.”
If you are interested in a fun, fascinating winter project, I recommend reading the following resources:
Happy Vermicomposting!
We love our worms! Photo: Lisa Mason


  1. Drainage from the bins is "leachate" and worm tea is made from bubbling a porous bag of castings in water for about 24 hours. I use a small air compressor in order to provide sufficient oxygen. An aerobic environment is critical to grow the right bacteria in the tea.

  2. This is so cool!! I would love to read an update about how your composting goes after a while, how much compost you have been creating, how much waste you are preventing through the use of compost over time, and how you are using it to create a more nutrient-rich environment around you. It would be wonderful to see the impact that one person, or one family can have through composting. Thank you for this post!