Ecology club students learn about growing worms to compost food scraps.

Thanks for being interested in Vermicomposting.  This section describes the in's and out's of worm composting. You will learn how to succeed in using worms to turn kitchen scraps into garden gold.

Vermicomposting Brochure: English
Worm Vendors

Each year in North Carolina, we burn or bury over 420,000 tons of food waste. This wasteful practice is costly to both taxpayers and the environment.

Instead of discarding food scraps, recycle them with the help of worms. Vermicomposting (worm composting) transforms kitchen wastes and newspaper into an excellent soil builder, to give you healthier blooms and bigger crops in the garden. Worm compost boosts nutrients available to plants and enhances soil structure and drainage.

Using worms to decompose food waste:

• Reduces household garbage disposal costs
• Produces less odor and attracts fewer pests than putting food wastes into a garbage container
• Keeps hard-to-process organic waste out of the landfill, reducing cost to taxpayers
• Saves the water and electricity that kitchen sink garbage disposal units consume
• Produces a free, high-quality soil amendment (castings or vermicompost) and compost 'tea' for the garden
• Requires little space, labor, or maintenance
• Provides worms for fishing and pet food
• Is a lot of fun, and puts you in control of turning waste into valuable resources right at home

The materials needed to start a vermicomposting system are simple and inexpensive. All you need is a worm bin, worms, water, bedding (like newspaper) and your food scraps.

Worm Bin

You can make an inexpensive bin from a 16-gallon plastic tote. This is a low cost and proven way to get started in worm raising. As you gain experience and become more interested, you may want to make a larger worm farm from wood (Worms Eat My Garbage has a good plan), try a commercial system, or create an outdoor system. The bin we suggest uses a design perfected by vermicomposting authority, Kelly Slocum.

For two people (producing approximately 3 1/2 pounds of food scrap per week), a single tote bin is adequate, although some households prefer to have two or more.

Redworms (the type used for vermicomposting) thrive in moist bedding in a bin with air holes on all sides. Keep a lid on the bin, as worms like to work in the dark. Keep the worm bin where the temperature ranges between 55° and 77°F. Worms can't handle freezing or the direct summer sun. The garage is ideal, or out on a shady patio or porch in the warm months.

Worm farming uses a special "composting'" worm, the redworm or "red wiggler" (Eisenia fetida). Night crawlers are great in the garden, but won't do the job in the worm bin.

Beginning worm farmers get their starter worms from friends, bait shops, nurseries, or by mail from commercial worm growers. Commercial growers are the most reliable and economical source of good healthy worms. If you want to purchase worms please call us at 704-336-5359 for local vendors.

These worms will keep reproducing – fast!  There are about 1000 worms in a pound, and soon you'll have more than 2000. Take a look under "Harvesting"  section for suggestions on how to manage your expanding herd. One of our participants has been going 6 years on his original worms (from a bait store on Albemarle Road) without buying replacements – and has given away a large number of worms to teachers, friends and other interested in vermicomposting for themselves.

Bedding must remain moist. Before filling a new bin, tear your newspaper into 1 inch wide strips and soak it for one half hour in water. Let the paper drip drain, then add it to the bin. If the bedding dries out, use a plant mister to spritz some water on it or water lightly with a watering can. The bin needs to be more moist than your outdoor compost pile. The ideal moisture level is roughly 80%, like a very moist sponge.

The worms need bedding material in which to burrow and to bury the garbage, and to hold moisture. It should be a non-toxic, fluffy material that holds moisture and allows air to circulate. Suitable materials include shredded paper (such as black-and-white newspapers, paper bags, computer paper, or cardboard); composted animal manure (cow, horse, or rabbit); shredded, decaying leaves; peat moss (which increases moisture retention); or any combination of these. Do not use glossy paper or magazines. Worms will eat the bedding, so you will need to add more within a few months.

Some successful worm farmers add two handfuls of soil to the bedding in each bin to supply "roughage" for the worms. Adding crushed eggshells provides not only roughage but also calcium for the worms, and it lowers acidity in the bin. Some people also add a handful of rock powder. Others feel the food scraps provide enough grit.

As a practical matter, soil is free and readily available, so why not?

Newspaper works adequately as bedding, and – best of all in Charlotte – if you subscribe to a newspaper you get all the bedding you need. A four-inch stack of newspapers, torn in 1-inch strips, provides more than enough bedding for a tote-type bin. Other materials will also work, including shredded leaves or cardboard. Some commercial systems advocate special beddings, such as coconut waste or "coir."  These products may be excellent bedding, but they are not necessary.

Newspaper can take a while to break down into an appealing bedding. Be patient, after a couple of weeks you will start to see the change. Using newspaper or waste paper helps cut down on waste.

Feed your worms any non-meat organic waste such as vegetables, fruits, eggshells, tea bags, coffee grounds, paper coffee filters, and shredded garden waste. Worms especially like cantaloupe, watermelon, and pumpkin. Limit the amount of citrus fruits to prevent the bedding from becoming too acidic. Break or cut food scraps into small pieces so they break down easier. Do not add meat scraps or bones, fish, greasy or oily foods, fat, tobacco, or pet or human manure.

Be sure to cover the food scraps completely with the bedding to discourage fruit flies and molds.

One pound of worms will eat about three and one half pounds of food scraps a week. If you add more food than your worms can handle, anaerobic conditions will set in and cause odor. This should dissipate shortly if you stop adding food for a while.

Location, location, location: Begin by deciding on where you'll put your worm bin. Popular indoor spots are the kitchen, pantry, bathroom, mud room, laundry room, or basement. If you want to keep your worm bin outside, put it in the shade during the hot summer. Shelter it from the cold in winter by placing it in a garage or carport, or by putting hay bales around the bin to allow air circulation while blocking cold and wind. Always protect the bin from flooding, because the worms can drown.

Making the bed(ding): If you want to use newspapers, fold a section in half and tear off long, inch wide strips (go with the grain of the paper and it will tear neatly and easily). Soak the newspaper in water for several minutes, one half hour maximum, then wring it out gently. Fluff up the newspaper as you add it to your worm bin. The bedding should be very damp, but not soaking wet (only two to three drops of water should come out when you squeeze the bedding material). Spread the bedding evenly until it fills about three-quarters of the bin. Sprinkle a couple of handfuls of soil (from outdoors or potting soil) into the bedding to introduce beneficial microorganisms and aid the worms' digestive process. Some experienced wormers like to fluff up the bedding about once a week so the worms can get plenty of air and freedom of movement-others believe in a policy of strict non-interference.

Settling in: Gently place your worms on top of the bedding. Leave the bin lid off for a while so the worms will burrow into the bedding, away from the light. The worms will not try to crawl out of the bin if there is light overhead.

Once the worms have settled into their new home, add food scraps that you have been collecting in a leak-proof container. Dig a hole in the bedding (or pull the bedding aside), place the food scraps in the hole, and cover it with at least an inch of bedding. After this first feeding, wait a week before adding more food. Leave your worms alone during this time to allow them to get used to their new surroundings. Bury food scraps in a different area of the bin each time. Worms are always hungry, so you can feed them any time, day or night. Do not worry if you must leave for a few days, since you can feed them as infrequently as once a week.

Other critters: Do not be surprised to see other creatures in your worm bin, as they help break down the organic material. Most of the organisms will be too small to see, but you may spot white worms, springtails, pill bugs, molds, and mites.

After about six weeks, you will begin to see worm castings (soil-like material that has moved through the worms' digestive tracts). Castings can boost plant growth, since they are rich in organic matter and the nutrients plants need to thrive, and are pulsing with biological activity that will bring life to your soil eco-system.

In three or four months, it will be time to harvest the castings. The mix of castings and partially decomposed bedding and foodscraps, along with the worms themselves, is called vermicompost… Most home worm farmers harvest and use vermicompost instead of "pure" castings. Vermicompost is much easier to harvest and gives many if not all of the same benefits in the garden.

There are different ways to handle harvesting:

Simple: You can remove about half of the worm castings and put that on the garden, worms and all. Redworms will not generally survive long in garden soil, but do no harm (if you have deep organic mulch, some worms may survive for a considerable period). Add fresh bedding to the remaining vermicompost to refill the bin. The cocoons and worms in the castings will quickly recolonize the bin.

Recycling the worms: Place food scraps on only one side of your worm bin for several weeks. Most of the worms will migrate to that side of the bin. The remove the vermicompost from the other side of the bin where you have not been adding food scraps, and add fresh bedding. Repeat this process on the other side of the bin. After you have harvested both sides, begin adding food scraps to both sides of the bin again. Some commercial composters, like the "Can'O'Worms," uses a more complex version of this technique.

Sorting worms: This is the best technique if you want to harvest worms for sale, fishing or sharing with friends. Experiments with worms often require careful sorting and counting as well.

Empty the contents of your worm bin onto a plastic sheet or used shower curtain where there is strong sunlight or artificial light. Wait 20-30 minutes, then scrape off the top layer of vermicompost. The worms will keep moving away from the light, so you can scrape more compost off every 20 minutes or so. After several scrapings, you will find worms in clusters; just pick up the worms and gently return them to the bin in fresh bedding.

Be on the lookout for worm eggs; they are lemonshapped and about the size of a match head, with a shiny appearance, and light-brownish color. The eggs contain between two and twenty baby worms. Although it is time consuming, you may want to return the eggs to your bin so they can hatch and thrive.

Use your vermicompost immediately or store it and use it later.

Mix it into the top six inches of soil in your garden and around your trees and yard plants. You can also use it as a top dressing on outdoor plants or sprinkle it on your lawn as a conditioner. Vermicompost makes a great nutrient-rich mulch.

For indoor plants, mix vermicompost with potting soil. For top dressing indoor plants, remove any unsightly decaying bedding and food scraps from the castings (most of the castings themselves will be black, crumbly and have a faint pleasantly earthy smell). Remove worms and eggs, which cannot survive in an indoor pot.

You can also make a "compost tea" to feed to your plants. An easy recipe is to add two tablespoons of vermicompost to one quart of water and allow it to steep for a day, mixing occasionally. Water your plants with this "tea" to give them a boost.

Wherever human activities generate food scraps or organic wastes, vermicomposting can transform 'garbage' into a valuable resource. Worm composting bins have a place in classrooms, apartments, offices, and other commercial locations.

Large-scale worm farms exist many in states, including California, New York, Rhode Island, Washington, and Oregon, as well as right here in the Carolinas.

Vermicomposting is even helping to solve North Carolina's hog waste problems.

Classrooms and outdoor centers are especially appealing settings for worm composting. Children of all ages enjoy classroom activities involving worms. Several curricula on worms are available for classroom use, and teachers and parents can use worms in a multitude of disciplines, including science, mathematics, geography, language arts (vocabulary, poetry, and prose), and even music.    

 Sources of Additional Information and Supplies

Worms Eat My Garbage by Mary Appelhof. At the 'Wormshop', we sell the latest edition of Mary Appelhof's wormderful classic guidebook, Worms Eat My Garbage. This book launched the home worm-composting movement. The cost is $15, and we highly recommend it.

North Carolina Cooperative Extension Service Department of Biological & Agricultural Engineering North Carolina State University Box 7625 Raleigh, NC 27695-7625 Attention: Rhonda Sherman, Telephone 919-515-6770

Directory of Vermiculture Resources: Worms, Supplies, and Information (This guide lists resources nationwide and is available from Rhonda Sherman, address above).

Division of Pollution Prevention and Environmental Assistance, North Carolina Department of Environment, Health, and Natural Resources, P.O. Box 29569, Raleigh, NC 27626-9569, Telephone 919-715-6500, 800-763-0136.

Websites: Many excellent websites exist. A good starting point is: http://www.wormdigest.org

e-mail: sherman @eos.ncsu.edu

Based on the North Carolina State Cooperative Extension Vermicomposting Guide By Rhonda Sherman Edited (Jan. 2001) and adapted for Mecklenburg County PLANT 'wormshops'
by Don Boekelheide (dboek@aol.com)

We thank Ms. Sherman for her support and many contributions to the PLANT program.

We also thank Kelly Slocum and Mary Appelhof.