Most people know that worms have something to do with decomposing matter, but not everyone is aware of the central role worms can play in producing compost. If you're working with worms in compost, it's important that you have a clear understanding of the different conditions that must be in place for you to help your worms do the best job possible.
Not all worm species are created equal, especially when it comes to composting. Unlike true earthworms, compost worms do not live under the ground's surface; rather, they choose to live in areas above the ground where they can find organic matter to eat, such as a pile of manure or dead leaves. The two most common species used for vermicomposting are Eisenia fetida and Lumbricus rubellus. E. fetida, also called the red wriggler, is red with yellow and dark red stripes down its body. L. rubellus is also red but doesn't have any stripes; rather, it has a yellowish underbody. According to "Plants and Gardens News" associate editor Niall Dunne, L. rubellus may be contributing to the destruction of certain rare ferns and plants in North American, including the goblin fern.
Your worms and your compost are only as good as the bin you use. Commercial worm bins are available but you can also use a plastic or wooden bin that is no more than approximately 18 inches tall; drilling 1/4-inch holes in the bottom and sides of your bin keeps it from getting to waterlogged. According to Santa Cruz County Department of Public Works, you should allow approximately 2 square feet of surface area per person in your household when determining bin size. (see reference 2) A cover gives your worms the darkness that they love.
Your initial bedding for your compost worms should be a mix of different materials. Excellent choices include shredded cardboard and newspaper, straw, brown leaves and finished compost. Placing a bit of soil in your bedding (a handful or two) helps the red worms digest the food more quickly. Keep a spray bottle handy so you can spray the bedding regularly in order to keep it moist, like the worms prefer; you want the bedding to be about the consistency of a wrung-out sponge.
Compost worms require certain types of kitchen scraps, including spoiled vegetables, fruit peels, coffee grounds and even eggshells, as long as you crush them. You can also include thin, paper-like materials, such as napkins and tea bags. Scraps to avoid--due to possible odor and rodent problems--are meats, dairy products and greasy foods. Make sure you bury the food in the bedding to allow the worms to get to it better and to reduce possible odor issues.