How to choose container

When choosing your bins, determine how many worms you will want.

The larger you make the container, the more worms it can sustain. Estimate one pound of worms for every square foot of surface area. One pound of worms is able to compost a ½ pound of food per day.

Keep the depth no more than 24 inches deep because composting worms will not go further down than that.

Also, use a second container underneath to collect drainage.

Once you have your bin you need to make sure it is ventilated.  For plastic, drill several 1/8 inch holes about 4 inches from the bottom (this is NOT for the bin that you will use for drainage).  If you don’t drill the holes, the worms will stay at the bottom of the bin and you may drown them. Untreated wooden bins are naturally ventilated because of the structure of wood.

Your bin will also need a cover to prevent light from getting in and to prevent the compost from drying out. Choose or make a lid that can be removed if your compost is too wet.  You can use a canvas tarp, doubled over and bungee-corded on, or kept in place with wood. Burlap sacks also work well, and can be watered directly. You can also simply use a cover that comes with the rubber storage totes.

How to prepare the box for worms

Fill your bin with thin strips of paper scraps, unbleached corrugated cardboard or shredded newspaper, straw, dry grass, or something similar. This provides a source of fiber to the worms and keeps the bin well-ventilated. Sprinkle a handful of dirt on top, and thoroughly moisten. Allow the water to soak in for at least a day before adding worms.

What types of worms to buy and where to get them

There are several varieties of worms that are bred and sold commercially for vermicomposting; just digging up earthworms from your backyard is not recommended.

You can find worms all over the place online.  Also local gardening clubs are a good place to start.

The worms most often used are Red Wigglers.  Another variety to consider are European Night crawlers. They do not reproduce quite as fast as the red wigglers, but grow to be larger, eat coarser paper and cardboard better, and seem to be heartier.

Feeding the worms

The types of food you can put into your compost bin are fruit and vegetable scraps, coffee grounds, tea bags, and crushed egg shells. Limited amounts of breads and starchy foods are okay, but avoid citrus and onions because they can be too harsh for worms. Dairy, meat, or anything oily should not be added because it will cause the bin to stink. If you just stick to fruits and vegetables with enough bedding, the bin won’t have any smell at all.

Feed the worms gradually until you get an idea of how much they eat. Worms eat about half their weight in food everyday, so a pound of worms could eat 3-4 pounds of food in a week. (The worms are feeding on the microorganisms on the food, not the food itself.)  Feeding lightly and often will produce more worms.

Add more cardboard, shredded newspaper, hay, or other fibrous material once a month, or as needed.

How do you harvest worm castings.

Put on rubber gloves, and move any large un-composted vegetable matter to one side. Then, with your gloved hands, gently scoop a section of worms and compost mixture onto a brightly lit piece of newspaper or plastic wrap. Scrape off the compost in layers. Wait a while giving the worms time to burrow into the center of the mound. Eventually you will end up with a pile of compost next to a pile of worms. Use your fresh compost in the garden or where ever it is needed and return the worms to the bin.