Often called red worms, compost worms convert food scraps into nutrient-dense humus for a gardener to use on the garden and potted plant soil. As the worms reproduce, the composter can start additional worm bins or sell excess compost worm population to anglers or other composters. Weigh weekly food scraps before purchasing any compost worms, so you have a clear idea about how many pounds of worms you can feed with the amount of waste your household produces.
Prepare an adequately-sized (12- to 15-inch-tall) wooden or plastic bin for your compost worms. Provide approximately 1 square foot of surface space for each pound of weekly food scraps you plan to give your compost worms. For example, if you produce 8 pounds of food waste each week, then you may choose to use one bin that measures approximately 2 feet by 4 feet, or two bins that each measure 2 feet by 2 feet. Drill 10 to 15 3/8-inch, evenly spaced drainage holes in the bottom of each worm bin.
Fill your worm bin three-quarters full of shredded bedding materials, such as newspaper or dead leaves. Add the bedding to the bin in 3-inch increments, misting each layer down with a water-filled spray bottle until it's about as damp as a wrung-out sponge. Sprinkle two to three handfuls of plain topsoil into the bedding to give your compost worms a source of grit, which allows them to digest the food waste more quickly, according to Loren Nancarrow, co-author of "The Worm Book."
Place your red worms in the center of the bedding and cover the bin loosely with a single sheet of cardboard. Set the worm bin in a dark, warm location, such as a basement, monitoring the bin temperature regularly to ensure that it remains between 55 and 70 degrees F, the ideal temperature for compost worms, according to Nancarrow.
Feed your compost worms at least once per week, providing mild food scraps, such as fruit waste, vegetable peels and grain products. Bury the food waste under several inches of moist bedding to minimize foul, pest-attracting odors. Deposit the food scraps in a different area of the worm bin each time you feed your worms, to minimize waste buildup in the bin.
Push finished worm bedding to one side of your worm bin approximately 10 weeks after you began feeding your compost worms. Add fresh bedding material to the empty side of your worm bin. Wait several days to allow your worms to move to the fresh bedding before scooping the finished compost from the bin with a small trowel. Watch as you scoop to make sure you don't remove small, lemon-shaped worm cocoons.