Onondaga County Resource Recovery Agency - Indoor Composting

“Composting” and “indoor” in the same sentence? Yes!

Vermicomposting is the process of using worms to break down food and turn it into compost in your home. This is ideal for apartment dwellers, classrooms, and others who are not able to have a compost pile in their backyard.

Benefits

• Food scraps that would otherwise be wasted are turned into
   high-quality, natural fertilizer that you can add to plants and
   gardens to help them grow faster and healthier.

• Reduces the amount of trash your home generates.

• Keeps food waste out of waste-to-energy and
   water treatment facilities.

• Requires little space, labor, or maintenance.

• It’s a fun learning experiment for adults and kids.

Build a Worm Bin

Get started! View a step-by-step video on how-to build a worm bin.

Starting the Process - Location, location, location!

The worms prefer dark and quiet conditions, so you want to avoid bright light, vibration, and excessive noise for your worm bin.

Bin must be in a place where the temperature range remains at 55o – 85o at all times for the worms to survive and do their job.
Popular spots: kitchen, basement, pantry, mudroom, closet, or laundry room.

What You Need

• Plastic Tote Bin
• Lids (two)
• Mesh Screen
• Shredded Paper
• Spray Bottle of Water
• Peat Moss
• Soil
• Red Wiggler Worms
• Food Scraps

What to Do

Pick up a plastic tote from a home improvement store, and wash and rinse it out. (A typical worm bin is about 2 ft wide x 3 ft long x 1 ft deep.)

For aeration and drainage, drill about a dozen – ½“ holes around the top and bottom of the bin.

Holes on the upper sides of the bin will help your worms get oxygen and get rid of the carbon dioxide, and they will help prevent any odors from building up in your bin. And in case the bedding gets too wet, excess moisture will be able to escape through the holes in the bottom.

Remember to get two lids. Worms like to work in the dark, but they also need air circulation, so keep a loose-fitting lid on top of the bin. Place the second lid, upside down, underneath the bin to capture any moisture that may leak out.

Cut a piece of mesh screen to fit the bottom of the bin and place it in first. This will allow any excess moisture to escape through the bottom without the worms falling through. You can mix this excess moisture with water to make homemade fertilizer, or compost tea, that you can use to water your indoor and outdoor plants.

Add an even layer of shredded paper on top of the mesh screen. You can use newspaper, junk mail, or other paper you would like to recycle, as long as it is not glossy or printed with color inks. (Colored ink is toxic to the worms.)

Worms breathe through their skin, and in order to breathe their skin must be wet, so you will need to add water to the paper. If the bedding gets too dry in the bin, the worms will not be able to breathe and will die. You can wet the paper as you drop it in, or you can spray it after you put enough paper in to cover the bottom. Aim for the bedding to be damp – not too dry, but not soaking wet (two or three drops of water might fall when you squeeze a handful of paper). Wring it out and fluff it up – never leave wet paper compacted in the bin as air circulation is a must.

Add a layer of peat moss that does not have any added chemicals or fertilizers. The worms will eat this along with the food scraps. Peat moss will help the worms digest by adding roughage to their diet, and it will provide more air circulation.

Again, you will want to add water to the bedding. Just spray a small amount of water on the peat moss, so that it’s not bone-dry. You want it to maintain its “fluffiness.”

Add a thick layer of moist soil to the bin. Do not add soil that has added chemicals or fertilizers. You can use soil from outdoors or purchase potting soil. Like the peat moss, the soil will help the worms’ digestion process. Soil will also introduce beneficial microorganisms to the worms’ new home.

Worms

You must use red wiggler worms (eisenia fetida) for your indoor vermicompost bin, as opposed to outdoor earthworms, because:

• Even though they are smaller (usually grow to 4” long or less), they will eat a much larger amount of material – they can eat over half their weight of garbage in 24 hours!

• They will cut the composting process time in half, compared to bacteria alone.

• They reproduce quickly, but they will regulate their own population if it becomes too crowded (you don’t have to worry about too many worms overloading the bin).

You should start with about 1 pound of red wigglers. You may purchase them online. Usually, one pound will cost about $20-$25. Be sure to select a business that will guarantee their arrival within 1-2 days, because they probably won’t survive much longer than that in the mail.

Gently place the worms on top of the bedding. Do not expose them to direct sunlight, as this may harm them.

Give them a minute to burrow down into the soil and get comfortable in their new home.

Feeding

You can feed them a variety of compostable food scraps that are suitable for an indoor bin. See chart below.

This means fruits, veggies, bread, cereal, and tea leaves and bags. You can also feed them coffee grounds and filters once every week or so. Do not feed them any meat or dairy products, and do not put any F.O.G. into the bin – fats, oil, or grease.

You can collect the food in any type of sealed container (to keep odors in) and keep it under your kitchen sink.

To speed up the process, cut food scraps into ½” pieces before you add them to the bin.

Dig a small hole in the bedding / pull the bedding aside, and place the food scraps in the hole. Cover the food with at least 1” of existing bedding, or add more soil on top of the food. It is important to completely cover the food to avoid any odors.

Acceptable Items

Coffee grounds and filters
Egg shells (pulverized)
Fruit peels and pulp
Paper (shredded)
Tea bags and filters
Old bread
Vegetable scraps

Unacceptable Items

Ashes
Dairy products
Fish
Grains
Greasy or oily foods
Meat and other animal products
Pet wastes
Glass, plastic or tin foil

Tips

• After this first feeding, wait a week before adding more food. Leave them alone during this time to allow them to get used to their new surroundings.

• Feed them 1-2 times per week. The amount of food and how often they should be fed will depend on how quickly the worms are able to break down the food.

• Fluff up the bedding about once/week so the worms can get plenty of air and room to move.

• Check on the moisture level once a week and add water if it is too dry.

• Bury food scraps in a different area of the bin each time.

• Sexually-mature worms have dark red bands around their necks. Every few months, they'll congregate into one huge, squiggling ball at the bottom of your bin. When you see that, you know that it's time to hang the "Do Not Disturb" sign.

• You will eventually find worm eggs! They are lemon-shaped, have a shiny appearance, and are about the size of a match head. They begin as pale yellow when first laid, and become more brownish in color. Each egg will contain 2-10 baby worms, which will hatch after 3 weeks. Once they hatch, they can reach maturity and begin laying eggs at 6 weeks old. With a lifespan of one year, red wigglers can lay eggs every week after maturity. You do not need to be concerned with overpopulation, because they will regulate their own population to suit their environment.

Results

After about 6 weeks, you will begin to see worm castings. This is a soil-like material that has moved through the worms’ digestive tracts.

In 3-4 months, it will be time to harvest the castings or vermicompost. After harvesting, the compost can be mixed with potting soil and used for houseplants. lt can be used directly in the garden, either dug into the soil or used as a mulch.

Check out the links below for details on how to do this properly harvest your vermicompost as well as troubleshooting tips.

If you have questions or need more information, send us an email.