Worm Composting

What Is Worm Composting?
Worm composting is a great way to recycle leftover food and other organic material. Like backyard composting, worm composting creates an ecosystem containing worms, bacteria, mold, and other microorganisms that break down organic material.

Red worms are the best type of worm for consuming leftover food in a bin. Their castings, or manure, are primarily responsible for producing the compost. This is how most of the organic portion of the soil is formed. Soil is made up of sand and clay particles, organic material (humus), and the organisms that cycle the nutrients.

  • 2 cups of soil or compost
  • Red worms (elsenia fetida), also called "red wigglers"
  • Scale
  • Shredded newspaper (bedding)
  • Water
  • Worm bin
  • Worm food
Determine the average amount of food waste you produce each day. The ratio of worms to food is 2:1 by weight. If you produce a 0.25 pounds of food each day, you will need a 0.5 pounds of worms

Types of Worm Food

  • Bread
  • Cereals and grains
  • Coffee grounds and filters
  • Crushed egg shells
  • Dead house plants
  • Fruit and vegetable scraps
Do not put any meat, oil, or dairy products into worm bin.

1.What size worm bin do I need?
The ratio of worms to space is 1:4. 1/4 pound of worms will need 1 cubic foot of space (1 foot high by 1 foot wide x 1 foot long). About 1/2 pound of worms will need 2 cubic feet of space (2 feet long by 1 foot high by 1 foot wide). A large surface area allows adequate oxygenated air to reach the worms. Drill some holes in the bottom and sides of the container to allow for additional air circulation and water drainage. You may need to cover the bin to ensure that it is dark enough for the worms.
2.How much bedding and water will I need?
Tear 2.5 pounds of newspaper into strips for each cubic foot of bin space. Tearing the paper lengthwise is easier than tearing it widthwise. A 2 cubic foot bin will need approximately 5 pounds of shredded newspaper. You will need to moisten the paper with water. Worms are between 75% - 90% water. The surface of a worm must be moist for the worm to respire (to exchange carbon dioxide and oxygen). To ensure that you have added enough water, shred the paper into a sink or other container and then add enough water so the paper is covered. Lift the paper out of the water, allowing the excess to drip off. Place the wet newspaper into your bin.
3.How do I make the worm bin?
Add 1 or 2 handfuls of soil or compost to the moistened bedding to provide grit for the worms' gizzards. Like birds, worms use gizzards for grinding up food. Remember, worms don't have teeth! The soil or compost, along with a few handfuls of leaves, strengthens the bin ecosystem by providing other organisms found in a compost food web. Now you may bury your worm food and add your worms.
4.Where can I get worms?
Many bait stores sell red worms. You can sometimes find worms in rich moist soil around your house or compost pile, but be sure to get red worms.
5.How do I take care of my worm bin?
Provide the worms with food, adequate moisture and air. Check the bin while you are adding food to see that the bedding has not become too matted or is drying out. Daily care is unnecessary. You may feed your worms once a day or once a week, whatever fits best into your schedule. Bury the food by creating a pocket in the bedding and covering it. Bury worm food in a new location each time. Worms will freeze, so keep your bin's temperature above 50 degrees.
6.How do I know when my worm bin is done?
It will take about 6 weeks before you see noticeable changes in your bin. Once the newspaper has been replaced by castings, the concentration of castings will begin to become toxic to the worms. This process generally takes 2 - 4 months. At this point you will need to remove the castings and separate out the worms before preparing new bedding.
7.What can I use the worm castings (compost) for?
- To start seedlings
- As a top dressing for indoor or outdoor plants
- Mixed in with potting soil
- Use as mulch
8.What are 3 methods for harvesting your compost?
- Dump out the contents of your bin and form many small piles. The worms will go to the center of each pile to hide from the light. Prepare the bin with fresh bedding. Put the worms back into the bin. Gather up the worm-free compost to use as desired.
- Push your compost and worms over to one side of the box. Fill the other side of the box with fresh bedding and food. Begin burying your food scraps only on the new side. In their search for food, the worms will migrate over to the side with the new bedding. In a few weeks, you can take out the worm-free compost.
- Dump 2/3 of your bin, worms and all, into your garden. Add fresh bedding and food to the bin for the remaining worms.