How to Compost Indoors With Worms

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Red wriggler earthworms

Red wigglers are the recommended type of earthworm to use for vermicomposting.

Looking for an interesting winter project and a way to get rid of the vegetable and fruit scraps left over from your Thanksgiving meal preparations? Want a free source of natural fertilizer for your plants? Like the idea of cohabiting with earthworms? Then vermicomposting is just what you need!

Vermicomposting is a method of composting that uses worms to break down kitchen scraps into a rich, soil like material known as worm castings. Vermicomposting takes up little space and can be done indoors or out. To get started you just need to know a little about the basic supplies and procedures for keeping a worm bin.

Making the Worm Bin

Worms for vermicomposting are kept in a bin along with their bedding and food supply. Commercially made bins are available online and from some garden centers, or you can easily make an inexpensive bin from readily available materials. For most folks a 2’ x 3’ bin made from a plastic storage container is a great way to start. Choose a container that is dark in color, at least 12” deep, and has a tight fitting lid. Drill six ½” holes around the upper side of the bin to allow air in and six ¼” holes in the bottom to allow excess moisture to escape.

Next fill the bin half full with bedding material. This is what the worms will live in instead of soil. You can use shredded newspaper, paper (non-glossy only), or cardboard, brown leaves, sawdust, or a combination of these materials. Soak bedding in water for several minutes and then wring them out before placing in the bin. Then fluff the bedding material up and add a handful of soil. Your bin is now ready to be filled with worms.

The Right Worms

For vermicomposting not just any old worm will do. Of the 4,000 or so different types of earthworms, red wigglers are the recommended species. Red wigglers are not the same as the earthworms most of us dig up in our garden. They can be ordered online from worm farms, and generally cost around $30 per pound, including shipping. To get started you will need a pound of worms (around 1000 worms).

Add your worms to the prepared bin and place it in a location where it will stay between 55 and 80 degrees most of the time, and will not receive direct sunlight. Worms can survive temperatures as low as 32 degrees; they just aren’t as productive when it’s cold. Ideal places for worm bins include the laundry room, kitchen, bathroom, or garage. You can keep bins outside, as long as they are shaded from direct sun and you insulate them in the winter with hay bales or foam board.

You will need to feed the worms once a week. You can give them chopped up vegetable and fruit scraps (avoid citrus peels though), coffee grounds and filters, tea bags, crushed egg shells, moistened bread, and shredded napkins. A pound of worms will need around ½ pound of food each week. To feed your worms, dig a small hole in the bedding for the food and cover with at least 2” of bedding to prevent odor issues.

Harvesting the Castings

Your first batch of castings should be ready in three to six months. To harvest the compost, encourage worms to move to one side of the bin by placing food on one side of the bin only for a few weeks. Harvest the vermicompost from the opposite half of the bin, and fill with fresh bedding. Repeat on the other side to harvest all the compost.

Vermicompost can be used as an amendment mixed into the soil to grow vegetables or ornamentals, mixed with potting soil for seedlings or houseplants, or as a top dressing for growing plants or lawns. You can also make compost tea, a natural alternative to liquid fertilizer, by mixing two tablespoons of compost per quart of water and allowing it to steep for a day.

Learn More

Visit your local Cooperative Extension office to learn more about gardening and landscape care. Go to to find your county Extension center.