Bedding

Bedding is a high C/N material that holds moisture, provides an aerobic medium worms can exist in, and allows you to bury the garbage in the box.  The best beddings are also light and airy, helping to maintain aerobic conditions.  Bedding must not be toxic to worms because they’ll eventually eat it.  Bedding starts out dry and must be first soaked in water and then squeezed out until it is merely very damp.  Several ordinary materials make fine bedding.  You may use a single material bedding or may come to prefer mixtures.

If you have a power shredder, you can grind corrugated cardboard boxes.  Handling ground up cardboard indoors may be a little dusty until you moisten it.  Shredded cardboard is sold in bulk as insulation but this material has been treated with a fire retardant that is toxic.  Gasoline-powered shredders can also grind up cereal straw or spoiled grass hay (if it is dry and brittle).  Alfalfa hay will decompose too rapidly.

Similarly, shredded newsprint makes fine bedding.  The ink is not toxic, being made from carbon black and oil.  By tearing with the grain, entire newspaper sections can rapidly be ripped into inch-wide shreds by hand.  Other shredded paper may be available from banks, offices, or universities that may dispose of documents.

Ground-up leaves make terrific bedding.  Here a power shredder is not necessary.  An ordinary lawnmower is capable of chopping and bagging large volumes of dry leaves in short order.  These may be prepared once a year and stored dry in plastic garbage bags until needed.  A few 30-gallon bags will handle your vermicomposting for an entire year.  However, dry leaves may be a little slower than other materials to rehydrate.

Peat moss is widely used as bedding by commercial worm growers.  It is very acid and contains other substances harmful to worms that are first removed by soaking the moss for a few hours and then hand-squeezing the soggy moss until it is damp.  Then a little lime is added to adjust the pH.

Soil

Redworms are heat-tolerant litter dwellers that find little to eat in soil.  Mixing large quantities of soil into worm bedding makes a very heavy box.  However, the digestive system of worms grinds food using soil particles as the abrasive grit in the same way birds “chew” in their crop.  A big handful of added soil will improve a worm box.  A couple of tablespoonfuls of powdered agricultural lime does the same thing while adding additional calcium to nourish the worms.

Redworms

The scientific name of the species used in vermicomposting is Eisenia foetida. They may be purchased by mail from breeders, from bait stores, and these days, even from mail-order garden supply companies.  Redworms may also be collected from compost and manure piles after they have heated and are cooling.

Nightcrawlers and common garden worms play a very important part in the creation and maintenance of soil fertility.  But these species are soil dwellers that require cool conditions.  They cannot survive in a shallow worm box at room temperatures.