RECYCLING WITH WORMS
It’s not unusual to recycle paper, glass and plastic, but when’s the last time you recycled a banana peeling? Or a tea bag? Or even your pizza crust? It’s true; your kitchen waste can be turned into a valuable resource. All it takes is a little time and a lot of worms. Yes, worms.
       Composting is the process of decomposition used to turn kitchen scraps, yard wastes and paper products into humus, a dark soil-like substance that is rich in nutrients. But not everyone has the space for an outdoor compost bin. That’s why composting with worms, known as vermicomposting, is growing in popularity. It requires little space and can be used indoors year round.
       Vermicomposting is healthy for the environment in several ways. First, it helps reduce the volume of waste in our landfills. It also helps divert the amount of food waste that is run through a garbage disposal and washed down the drain, where it flows into our water system. That’s important; because too much food waste in our water system can impact the balance of good bacteria and require more chemical treatment. Finally, vermicomposting provides a nutrient-rich and environmentally healthy gardening product.
       The types of worms most often used for vermicomposting are Eisenia foetida and Lumbricus rubellus, commonly known as red worms, tiger worms, brandlings, angle worms, manure worms or red wrigglers.  These types of worms work best because they reproduce quickly and they can consume large amounts of organic material. Worms for vermicomposting can be purchased at some gardening stores, bait and tackle shops and mail-order or Internet outlets.
       As worms consume foods and other organic matter, they break the material down into nutrient-rich compost. They eat by pushing their pharynx, or throat, out of their mouth and pulling food back in. Once inside, the food is moistened with saliva and pushed to the worm’s stomach, or crop. Food then goes into the gizzard where muscles and tiny particles of stone are used to grind the material. Next, the food moves into the intestine, where digestive juices continue the breakdown process. Some of the digested material then passes into the bloodstream and the rest is expelled as castings. That’s how vermicompost is created.

Building a Vermicomposting Bin
To reap the benefits of this process, create your own worm bin. Bins can be made of plastic or wood, although wood is more absorbent and provides better insulation. An old drawer or a plastic storage box will work fine. Pre-made compost bins also can be purchased.
       The bin should be shallow, from 8 to 12 inches deep, because the worms used for vermicomposting are top feeders. The length and width requirements for the bin depend on the amount of food waste your household produces. A 3-foot by 2-foot bin should be adequate for a family of four to six people. Some experts suggest one square foot of surface area per pound of food waste per week.
       To allow for water drainage and oxygen flow, drill 8 to 12 holes no wider than 1/8 inch in the bottom and sides of the bin, approximately 3 inches apart. The bin also will need a cover because worms don’t like light. The lid will also help conserve moisture and keep insects and other creatures out of the bin.
       Worm bins can be placed indoors or outdoors, but choose a place where the temperature ranges from about 55 to 77 degrees Fahrenheit. To allow for better airflow, raise the bin off the ground with wooden blocks or bricks. Use a tray or plastic sheet underneath to catch excess liquid, which can be used as a liquid plant fertilizer.
       To begin the vermicomposting process, add bedding for the worms. Shredded cardboard, newspaper, and computer paper are all inexpensive materials that work well. Just remember to use only newspaper with black ink because colored ink can be harmful to worms. Add a couple of handfuls of soil to the bedding as well, which will help the worms’ gizzards digest food. And most importantly, add enough water to make the bedding material’s moisture content about 50 percent, or as damp as a wrung out sponge. Remember, worms need moisture to survive.
       Once the bedding is prepared, it’s time to add the worms. The number of worms needed depends on the amount of food waste that will be added each week. About two pounds of worms for every one pound of garbage should be sufficient. By the way, it takes about 1,000 to 1,500 worms to weigh a pound.
       After the worms have settled into their new home, small pieces of food waste can be added. Start slowly in the beginning to allow time for the bacteria to form. The worms will also be eating the bedding material so don’t worry about them starving. To speed up the composting time, chop the food in a food processor before adding it to the bin. Then simply bury the food in the bedding material every two to three days. Choose a different spot each time the food is buried and work your way back to the original spot. If the bin becomes smelly, cut back on the amount of food added.
       The types of food that can be added include vegetable and fruit waste, bread and grains, crushed egg shells, coffee grounds and filters and tea bags. Avoid adding meat, dairy products, bones, oily or greasy food, garlic, onions and spicy foods. Citrus should be added sparingly, as it can make the compost too acidic.

Harvesting Vermicompost
After about three months, or when the original bedding material has disappeared, it’s harvesting time! There are several ways to harvest the vermicompost. One way is to move the finished compost to one side of the bin and add fresh bedding and food waste to the other side.  The worms will migrate to the fresh side and the finished product can be removed.
       Another way to harvest the vermicompost involves emptying the contents of the bin into piles on a large piece of plastic in the sun or under bright lights. The worms will move to the bottom of the piles to avoid the light. The top of the piles can be then be skimmed off. Do this several times until only balls of worms remain on the plastic. Then add fresh bedding to the bin and put the worms back in.
       After the vermicompost has been harvested, you have a valuable fertilizer with many uses. In the garden, it can be placed in a hole dug to plant a seedling. You can also put it at the base of houseplants to provide them with nutrients. Or, you can sprinkle it around the base of trees at your home, a city park or at school. And those aren’t the only benefits of vermicomposting. Since worms reproduce so quickly, you’ll have plenty of bait for your next fishing trip. But that’s a whole other can of worms.

GLOSSARY
vermicomposting — the use of earthworms to turn organic wastes into very high quality compost. The prefix comes from the Latin word for worm, “vermes.”
humus — the dark, organic part of soil that is derived from microbial decomposition of plant and animal materials.

CLASSROOM PROJECT
Build your own vermicomposting bin at school!
Get permission to recycle food waste from the cafeteria as a classroom project. Use only the food waste created during the preparation of meals; not scraps from plates. Collect the food waste three times a week and use a food processor to chop it up. Add it to your vermicomposting bin and see what happens. Don’t forget to keep the bin moist. Once the vermicompost has been harvested, students can take home worms and create a vermicomposting bin for their family.

Application
After harvesting your vermicompost, find out just how well it works as a plant fertilizer. To compare your vermicompost to other commonly used fertilizers, gather four different pots and fill them with regular topsoil. Purchase a package of seeds from a local garden center. Select a type of seed that will work well for the environment where the pots will be placed. For example, if the plants will be kept in your classroom, you might consider a plant that requires little light.
       Then plant the seeds in the same manner for each pot. Next, add an inch or so of vermicompost to cover the topsoil in the first pot. For the second pot, add a store-bought fertilizer. For the third, add cow or horse manure. And for the fourth pot, add nothing at all.
       When the plants start sprouting, measure them and keep a daily record of their growth. Which gardening system worked best?

SOURCES & SITES
Appelhof, Mary. 1982. “Worms Eat My Garbage.” Flower Press, Kalamazoo, Michigan.

Archer, Sarah. “Recycling: New Practices, Feed It to the Worms.” The Plant Exchange. University of Michigan. www.plantops.umich.edu/PlantExchange/2002-09/6.html

Dickerson, George W. “Vermicomposting: Guide H-164.” 1999. New Mexico State University Cooperative Extension Service. www.cahe.nmsu.edu/pubs (At this site, click Extension How-To Publications; then click Horticulture.)

“All About Earthworms.” 2000. Discovery Communications, Inc. http://yucky.kids.discovery.com/flash/worm/pg000102.html

“Vermicomposting: Indoor Composting with Earthworms.” Massachusetts Department of Environmental Protection. www.state.ma.us/dep/recycle/files/vermi.htm

“Worm Your Way Into Composting.” 2002. Pennsylvania Department of Environmental Protection. www.dep.state.pa.us/dep/deputate/airwaste/wm/recycle/Worm/worm1.htm

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Last Updated: 03/04/04
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