Worm Bin Composting
Let Worms Eat Garbage: Steps to Start Composting Food Waste With a Worm Bin
Gather the Materials Needed
- A Worm Bin:
A worm bin is a sturdy box with a tight fitting lid, and holes for drainage and ventilation. It can be made from an old cupboard or packing crate, or built from plywood and two-by-fours or purchase a wood or plastic bin. A shallow box, about a foot deep, is best because the worms need to live near the surface to breathe. Allow about one square foot of surface area for each pound of food waste added per week.
Use moistened shredded paper, sawdust or leaves as bedding. Bedding gives the worms a balanced diet and a damp place to live. Composting food wastes without bedding produces bad odors and a slimy mess. The nearest source of bedding is probably the Sunday paper. Tear the newspaper lengthwise into one to two inch strips.
- Red Worms:
Also known as "red wigglers" or manure worms, red worms thrive on organic materials like food scraps. Red worms are not the same as earthworms or night crawlers which prefer to live in soil. Start the worm bin with 1 to 2 pounds of red worms. Dig a starter batch of worms out of a friend's worm bin, or purchase them at a local garden supply store.
Set Up Your Worm Bin:
First choose a location for the worm bin that is protected from direct sunlight and extreme cold, and that has good air circulation. This location may be on the side of the house, on a patio or deck, in a garden, or in a basement or garage. Keep in mind that liquid may come out of the bin's drainage holes. Moisten the bedding by soaking it in water using a large mixing container like an empty garbage can. Squeeze out excess water until bedding feels like a wrung out sponge. Fill the bin 3/4 of the way to the top with loose bedding. Pull apart any compacted paper strips. Next dump the red worms on top of the fresh bedding. Gently break up clumps of worms and let them move down into the bedding.
Do Feed Worms:
- Vegetable scraps
- Fruit rinds and peels
- Coffee grounds, filters
- Tea bags
Do Not Feed Worms:
- Cheese, Yogurt
- Butter, Oily foods
- Pet wastes
- Plastic bags
- Other plastic, metal
Save Food Waste:
Collect the food wastes in a small container in the kitchen until ready to feed the worms. Do not add yard waste, soil or pet wastes.
Bury Food Waste In The Worm Bin:
About once a week, use a trowel or other tool to dig a shallow hole in the bedding of the worm bin. Dump the food waste into the hole. Always cover the food waste with at least one inch of bedding to discourage flies and odors. Bury food waste in a different spot each time to encourage the worms to move around the bin. When adding food waste, check the bedding in the bin to make sure it is moist. Add water with a spray bottle or watering can if it is too dry. If it is too moist, check the drainage holes on the bottom of the bin.
Harvest Compost And Prepare Fresh Bedding:
After a few months the volume of the bin contents decrease. At this point it will look more like compost (worm "castings") than bedding material. When this happens, push the contents of the bin to one side of the box. Put fresh bedding in the empty side and start burying food waste there. The worms will begin migrating to the fresh food. Leave the old side alone to finish decomposing. In a couple of months the old side will be vermicompost, a dark and crumbly soil-like material. Then remove it from the bin to use in the garden or with house plants. Fill that side of the worm bin with fresh bedding and start the process again.
Answers to Common Questions
- How To Control Fruit Flies?
Because of the nature of the material in the compost in a worm bin, it will probably always have a few fruit flies. Keep the flies to a minimum by fully covering fresh food wastes with a few inches of bedding and by covering the bedding with a sheet of plastic. To get the fruit fly population under control, try vacuuming them up.
- What Are The Other Critters In The Worm Bin? Will They Hurt The Worms?
Once the worm bin has been going for a while, other creatures like white worms, springtails, sowbugs and millipedes may live in the bin. This is normal, and these creatures will not hurt the worms. In fact, they help the composting process. The only bugs that may be present that pose a threat to worms are centipedes. To tell centipedes and millipedes apart look at how their legs are attached to their bodies. Centipedes have only one pair of legs per segment, millipedes have two pairs.
- The Bin Smells Awful! What To Do?
Unpleasant odors in a worm bin may result from too much food waste, too much moisture, or composting cheese or animal products. Control odors by removing excess or inappropriate wastes, making sure drainage holes are not blocked and adding more drainage holes or fresh bedding if needed. Always cover fresh food waste with at least one inch of bedding or worm castings.
- What Is Growing In The Worm Bin?
Occasionally patches of mold or sprouts grow in worm bins. Molds and fungi are a natural part of the composting process, helping to break down the food waste. Vegetables may sprout in the bin because of all the nutrients present. These things will eventually be consumed by the worms and other organisms. To keep the mold or sprouts out of sight cover them with bedding.
- What Happens To The Worms In The Winter?
When it gets colder, the worms will slow down, and will not be able to digest as much food waste. Cut back on the amount of food waste the worms receive between November and February. Red worms can survive cold winters outside if protected by bedding in a worm bin.
- How To Use The Vermicompost?
Vermicompost is extremely nutrient rich and helps soil hold moisture. Use the vermicompost sparingly, sprinkling some in the bottom of seed rows or transplant holes, or using as top dressing for house plants. Mix it with peat or other materials to make potting soil. To use the compost for house plants, it is recommended to "cook" the vermicompost between sheets of black plastic in the sun for a few hours. This will get rid of most of the critters found in the compost.
Email the Solid Waste Coordinator