CHICKEN FEED: Worms for Feed

Mix leaves, sawdust, scraps, yard manure, and a handful of worms, to produce year-round protein for your flock, as organic as you make it. Reap the extra benefit of top-flight garden fertilizer to use or sell. Chicken owners everywhere say they should have gotten "into worms" much sooner!

"How To"

Worm Composting on the Rise at Home


Copyright by Jim Jensen, Permission granted to copy or post with complete attribution in whole, without addition, deletion, or substitution.

Ancient cultures revered worms for the valuable role they play in the formation of rich agricultural soil. Charles Darwin observed the activity of worms and credited them with the fertility of farms the world over. For decades, worm farmers and anglers have practiced vermiculture in the pursuit of profit and recreation. Recently, however, homeowners and recycling managers have taken note of the potential of worms to help manage our "wastes."

Feeding redworms is a good way to make high-quality compost from vegetable and fruit scraps. Unlike garden earthworms or nightcrawlers, redworms (known scientifically as Eisenia fetida, or commonly as manure, striped, or brandling worms) thrive on high- organic wastes.

The use of redworms for home composting has been developing for many years and has been popularized during the past decade. Home-scale worm composting is widespread in the U.S. and Canada , and is supported by many recycling agencies and the health department.

How to Do Worm Composting

Worm composting requires four basic items: redworms, a worm bin, bedding for the worms to live in, and food scraps. Redworms thrive in a rich organic environment, with lots of decaying matter. They are capable of ingesting as much as their body weight in wastes each day. That means that for however much food scrap you generate per day, you'll need to grow a population one to two time that weight of worms.

Researchers have found that redworms thrive in the following optimum conditions:

• temperature: 65 to 80 degrees F (15 to 25 degrees C)

• moisture content: 60 to 80 percent (higher than conventional composting)

• oxygen: yes, the worm bed must be kept aerobic

• pH: greater than 5 and less than 9

Two to three pounds of red worms will start most home worm bins. For larger scale projects, plan to start with one pound of redworms for every one to three square feet of worm bin surface area.

Give your worms a comfortable home. A good worm bin is a sturdy box with a heavy, tight-fitting lid to keep pests out and moisture in. A worm bin can be made from an old cupboard or packing crate, or built with plywood and two-by-fours. A shallow box—12 to 18 inches deep—is best because the worms live near the surface to get adequate air. Drill holes in the bottom or otherwise provide for drainage. (An idea for just trying it out: Recycle an old styrofoam chest for worm composting by poking a few holes in the sides for ventilation, and make sure that there is never any standing water in the bottom of the chest.)

A worm bin should have about one square foot of surface area for each pound of food wastes added per week. For example, a two-foot by four-foot box is large enough for eight pounds of kitchen scraps a week—the amount produced by two or three adults. Generation of food scraps varies widely between households, so you may want to weigh your scraps for a week or two before deciding what size or how many bins you want to build.

Fill the worm bin with moist "bedding," which provides the worms with balance in their diet and a damp place to live. Composting food scraps without bedding can produce bad odors and a slimy mess. Common bedding materials include fall leaves, shredded newspaper or corrugated cardboard, old straw, coarse sawdust, and aged dairy or horse manure. Rabbit manure also works well. Moisten dry bedding materials by immersing them in water for several minutes before adding them to the worm bin. When the bedding is thoroughly wet, remove it from the water and wring out or drain excess water. Moist bedding should feel damp like a wrung out sponge.

Fill the bin to the top with loose bedding. This gives the worms maximum room to grow their population. Pull apart any compacted paper strips before adding them to the bin. If brown leaves or sawdust are used they may need to soak longer to become saturated.

Feed worms by burying vegetative food scraps in holes dug into the bedding. Bury scraps in a different spot each time to provide the worms with a balanced diet. Always cover food wastes with a few inches of bedding or worm compost (called castings) to discourage flies and odors. For best results, think of worms as strict vegetarians. Give them scraps of fruits and vegetables, grains, old bread, coffee grounds, used tea bags, and egg shells. But leave out oily foods, meat, seafood, or dairy products.

Every 3 to 6 months push the old bedding and decomposing scraps to one side of the bin, rebed the empty side, and start burying food wastes in the fresh bedding. Allow the older scraps to finish composting for another month or so before harvesting.

Harvesting Worm Castings or Worms

One of the real benefits of worm composting is producing worm excreta (known as castings) for use in your garden. After a few months, worm castings from a worm bin will look dark and rich, quite black. To harvest castings for garden use, simply move nearly finished compost to one side of the bin and fill the empty side with fresh bedding (composting reduces the volume of the wastes by over one half). For the next six weeks bury food wastes only in the newly bedded side of the bin. The worms will migrate over to the fresh food in the newly bedded side as the food on the other side finishes decomposing. When the old bedding and food scraps are completely composted, the castings can be harvested and replaced with fresh bedding. It takes from three to six months for fresh bedding to decompose. Thus a worm bin can complete two to four cycles each year.

Harvesting worms for fishing is easy. Just open the bin and pick a handfull out of the bedding. To harvest more worms, take a few shovelfulls of castings out of the bin and make small piles on a piece of plastic out in the sun or under a bright light. Let the piles sit for ten minutes, then pull away the surface layer of castings until you see worms. Repeat the procedure until the worms are concentrated at the bottom of the piles and are easy to harvest.

Preventing Trouble

Worm composting bins are relatively trouble free. The most common problem with worm bins is fruit flies in summer. Fruit flies can be kept to a minimum by always covering fresh food wastes with a few inches of bedding or castings, and by covering the bedding with a sheet of plastic or newspapers tucked in around the edges. If the worm bin smells bad, it probably has too much food waste in it, is too wet, or there is cheese or other animal products present. To eliminate bad odors remove excess or inappropriate wastes and add fresh bedding.

Case Studies

Food Lifeline, Seattle , WA
As a major distribution center for food banks and meal programs in Western Washington , Food Lifeline's mission has always focused on people. So it was with their decision in late 1990 to add vermicomposting to their organization's work plan.

Food Lifeline uses leaves from the campus where it is located as a bedding in the bins. This leaf bedding serves many important functions, while reducing yard waste recycling costs. It creates a textured material in which the worms live and move. It also holds moisture and allows air to move and penetrate throughout the bin. It also provides a source of carbon that supports decomposition by bacteria, which are another source of food to the worms. The ratio of food scraps to leaf bedding is approximately 2:1 by weight, or 1:3 by volume.

Preparing each bin for a composting cycle begins by putting 4 to 6 inches of coarse wood chips at the bottom of the bin to assist aeration from below and to absorb excess moisture that may drain from the materials above. As a result, leachate escaping from the bins has not been a problem.

Next a 6-inch layer worm-rich bedding is laid down, similar to the way The Worm Concern starts its windrows. Two or three times a week, Food Lifeline staff, supported by volunteers and labor from a neighboring rehabilitation facility, feed the worms. Feeding occurs in four steps. First, they collect, weigh, and move food scraps to the worm bins. Second, they open the bins and mix the food and leaves in the top 6 or 8 inches—the active composting layer—using a pitchfork. Then, shallow troughs are made in the active layer, where they place the raw feedstock. Finally, the food is covered and more leaves are placed over the top to conserve moisture and serve as insulation. Water is added if the contents appear dry.

The Food Lifeline project has as available equipment a 16 hp commercial yard waste grinder to shred and mix the food and leaves. Food Lifeline's staff found, however, that most of the food composted well over time without grinding. Some large or hard-skinned items, such as potatoes, carrots, squash, or melons can be hand-chopped with a machete.

.... To harvest the castings at the bottom of the bin, the active composting layer, containing the greatest concentrations of worms, is taken from the top with a pitchfork or garden rake and placed in another bin to start a new cycle. The finished vermicompost is dug out by volunteers and used in an on-site food-producing garden, thus "closing the loop" and further supporting the hunger-fighting mission of Food Lifeline.

The Food Lifeline project demonstrates that staff with a minimum of skills can be trained to maintain vermicomposting systems. The labor required can vary widely. Food Lifeline currently composts 1,200 to 1,600 pounds of food and leaves each week using 8 to 16 hours of labor.


Getting the worms to grow awhile before the chickens get to them is the goal on some free-range ranchettes. On others, getting an extractable supply of worms to feed to the chickens inside their coop is the goal. Or, to dry the worms and mix as a protein element in blended feed. To accomplish these, some ideas might be worthy of consideration:

1. Grow the worms in bins, and just take out the active top layer and scatter it around for the chickens. Most worm-growers suggest this.

2. Make a frame on the ground, and cover it with several movable hatches. Bury new kitchen scraps and manure, etc., in some hatches, while chickens get to scratch under other hatches.

One size I'd like to try is a frame about 18 inches board-width (or 0.5 meter), measuring about 8 by 8 feet (or 2.5 by 2.5 meters). This goes on the ground, perhaps sunk into the ground. If you are inclined to use it, heavy-gauge wire (NOT chicken wire --- it rusts in a few years and kills your fingers forever after) covers the ground to keep moles from coming up and eating the worms. I'm not inclined to use it, but maybe I will be.

Then make 16 hatches 2 feet square, with 1 by 1 inch board rims on the bottom side. Use these to cover the ground inside the frame. Fill the frame with loads of leaves, sawdust, earth, manures, chicken coop bedding. Prepare as suggested by YelmWorms and others. Wet it all down good, with a lengthy sprinkling of water over all. Add worms. Put on covers. Rotate the digging in of garbage and manure with the opening up of some hatches for the chickens. Maybe this will prove to be a "SELF-FEEDING WORM FRAME" (like the self-fertilizing salads made by growing greens under wire frames for the chix to eat as the greens emerge out of the wire.)

3. Make an enclosed frame, very much longer than wide. One end is the intake end, where new mixes of leaves, scraps, sawdust, manure, etc., are added and pushed gradually down the closed shute. The other end is open to the chickens. It might be about 8 feet by 2 feet, with a 2-ft square opening at the OUT end, or maybe the compost just falls out onto the ground (where it would get flung to, anyway, probably). The IN end might also be 2-ft square, with a hatch cover, or wire cover to let in rain.

4. Harvest worms on a tabletop, so the valuable compost can be separated from the worms. Use harvested worms directly into the coop, or dry them in several ways to then grind for feed components (80% protein, as much as dried fish, liver, any other meat source).

*Dry in oven with gas pilot light or electric lightbulb.
*Dry in greenhouse.
*Dry in water-heater or central heating closet.
*Dry worms in an ORGANDY-material "pillowcase" that zips or ties closed


Copyright © 2008 Vermiculture Canada
Last modified: 05/19/10