Worm bin composting, or vermicomposting for us who like to feel smart using big words, is a compact alternative to backyard composting. Worm bins are small enough to fit under your sink, the bins don’t smell, and the worms will not escape. People pay big bucks for vermicompost (aka, worm poop) to use as a natural fertilizer but your worm bin will supply you with vermicompost for free in exchange for vegetable and fruit scraps. Worm bin composting is great for:
• Apartment or Condo Dwellers
• People who prefer not to step outside in the winter
• People fond of exotic pets
Setting up a worm bin is easy. For a household of four to six people you need a bin about 1 ft x 2ft x 2ft. Plastic bins used for storage work great. Drill holes in the bottom and sides for ventilation and place a tray under the bin to catch any water that seeps through.
Next, gather four to six pounds of shredded paper and dead leaves to use as bedding. Soak the bedding in water to the consistency of a wrung out sponge. Remember a worm’s body is 75% water and they need a moist environment to survive (but they’re not big swimmers so don’t try to make an aquarium). Mix one cup of soil from outside with the bedding.
Finally, add the worms to their new home. You will only need a half pound of red worms to start. They multiply faster than rascally rabbits and soon you will have a pound of worms for every square foot. You can purchase locally produced red worms for $20 per pound through Alex McDuffie (firstname.lastname@example.org).
Red worms used in vermicomposting have a voracious appetite and will eat half their weight in food scraps a day. When adding scraps start slow and increase as your worms multiply. Bury the food in the bedding to avoid gnats and fruit flies and place a cover on the bin to hold in moisture and block out light.
You can keep your bin any place that is convenient to add scraps- a closet, under the sink, in the garage, just don’t let them freeze or get above 90 degrees. We keep several vermicomposting bins in the backroom of our office and have received very few complaints (with the exception of our coworker Susan who just pretends the worms aren’t there).
In three to four months, your vermicompost will be ready to use. If you don’t want to pour out the compost and pick out the worms (oh kids, I have a new game to play…) consider adding fresh bedding and food to one side of the bin and waiting for all the worms to move over to their new digs. Then scoop out all the vermicompost and make sure you don’t pull out any stragglers (try not to release any of the red worms into the wild since they are not native). Vermicompost can be used as a soil amendment for houseplants or a top dressing on outdoor flower and vegetable beds.
For more tips on building a worm bin read the vermicomposting sections of our yardwaste at home handbook: http://www.hcdoes.org/SWMD/Residents/Yardwaste/YWatHome_08.pdf.