Vermicomposting

Using Worms to Compost Kitchen Scraps

For those turned off by the higher level of maintenance of a traditional compost pile, there is another option: worms. Vermicomposting is another kind of composting in which the worms do all (or nearly all) of the work. Little setup is required. Vermicomposting is an ideal method for those interested in composting only food scraps.

Where to Vermicompost

Worm bins can be small enough to be used in an apartment or office setting, indoors or out. You can build a worm bin out of wood or simply use a plastic container. Worms thrive in the dark, so make sure your worm bin has a lid and its walls are opaque. The container will also require drainage and a few air holes. The worm composter should be between six and sixteen inches deep. Width is more important than height. The more surface area you offer your worms, the better your food scraps will decompose.

Your worm bin can go anywhere, so long as the temperature is between 50°F and 80°F. Choose an accessible location as you may be adding food waste daily. If placed outdoors, monitor the weather. Hot weather may overheat and kill the worms.

Preparing Worm Bin Bedding

Before adding food and worms, you must prepare bedding. Suitable bedding materials include peat moss, shredded newspaper, shredded corrugated cardboard, and even machine-shredded computer paper. Avoid glossy paper such as the ads section of the newspaper. Worms require moist – NOT wet – bedding. Prepare worm bin bedding by soaking the materials for ten to twenty minutes then wringing it out. The bedding should be very damp but not dripping wet.

How to Compost with Worms

Red wigglers, not earthworms, are used in vermicomposting. One pound of worms consumes two to three pounds of food each week. After you add food waste, cover the scraps with bedding. You can feed your worms fruit and vegetable scraps, crushed eggshells, coffee grounds, and tea bags. Do not give worms onions, citrus, or meat.

Scraps may be added as often as once a day, but if you add more waste than your worms are able to consume, then the excess will begin to rot and develop an odor. Extra food waste can be stored in a freezer. Scraps should be added at least every three days.

Maintain the moisture level of your worm bin by spraying bedding with water every few days. Be careful not to over-water your worms. Never pour water directly into the worm bin.

Your worms will develop vermicompost after about four months. The soil-like mixture of worm castings and decomposed food scraps contains nutrients such as nitrogen, calcium, and potassium that are important for plant growth. After harvesting the finished compost, add new bedding to your worm bin.

For more information on vermicomposting, contact the Oldham County Cooperative Extension Service at (502) 222-9453.

Educational programs of Kentucky Cooperative Extension serve all people regardless of race, color, age, sex, religion, disability, or national origin.

Sources: Ashley Osborne, Extension Associate for Environmental and Natural Resource Issues, University of Kentucky Cooperative Extension Service, “Constructing a Worm Compost Bin;” Rhonda Sherman, Extension Solid Waste Specialist, North Carolina Cooperative Extension Service, “Worms Can Recycle Your Garbage.”

Written by Lauren State, Oldham County Extension Staff Assistant. Reviewed by Michael Boice, Oldham County Extension Horticulture Assistant.