Vermicomposting

Monday, June 28, 2010





















Vermi-composting, also known as worm-composting, is the process of using worms to break down waste into soil-enriching compost. The worm castings contain humic acids that enrich soil and act as a natural pesticide. Worm-composting is easier to maintain than your typical outdoor compost bin system (the worms do all the work for you), and it proves environmentally friendly by reducing the waste that would otherwise go to landfills.

To get started, follow these instructions from Nancy Kreith, a master gardener with the University of Illinois Extension, and TGC’s Chicago-area Coordinator …

Step 1: Find a bin

Start with a 10-gallon (38-liter), dark, covered container. Drill about 50 1/8” holes into the container’s lid.

Step 2: Create the bedding

Shred newspaper. (Don’t use glossy paper, because the worms won’t be able to digest the wax.) Moisten the shredded paper with water until it feels as wet as a wrung-out spunge. Finally, add one pound of red wrigglers (approximately 1000 worms) and a handful of soil.

Step 3: Feed the worms

Do not feed the worms more than they can consume–1/2 pound to 1 pound of scraps per day. Worms are capable of breaking down the following food scraps: fruit and vegetable peels, crushed egg shells, used coffee filters with grounds, and used tea bags. Avoid any form of animal bones, meat, fish, poultry, mayonnaise, cheese, and butter.

Step 4: Maintain your compost

Add more shredded paper if the bedding becomes too wet, and add water if it becomes too dry. If you notice worms on the walls or lid of the bin, your bedding mixture may be off balance. The key to keeping happy worms is feeding them raw kitchen waste on a regular basis.

Step 5: Harvest your compost

The food and newspaper should be fully decomposed after about three months. It’s time to separate the worms from the compost when you see only trace amounts of food in your bin. What remains should be a dark, rich, soil-like matter.

For more information on vermicomposting, check out the TGC summer newsletter. Not on our mailing list? Send an email to Amy.McMillen@fao.org with the subject line “Subscribe to Newsletter.”