Vermicomposting uses worms, typically red wigglers, to break down food scraps into a nutrient-rich material called castings. The EPA lists worm composting as a practical option for indoor and small-space composting.
How it works
Worms live in a ventilated bin with moist bedding (like shredded paper). You add fruit and vegetable scraps, and the worms process them into castings you can use in gardens or houseplants. A healthy, mature bin of red wigglers can process roughly half its own weight in food scraps each day. Keep the bin out of extreme heat or cold.
Pros and cons
It is compact and odorless when maintained well, making it great for apartments. You do need to avoid overfeeding and skip meat, dairy, and oily foods. See more small-space ideas in our guide to apartment composting.
Setup and planning
Use a ventilated, opaque bin with moist shredded-paper bedding and red wiggler worms. Keep it in a temperature-stable location away from direct sun. Begin with small amounts of fruit and vegetable scraps buried beneath bedding rather than filling the bin immediately.
Ongoing routine
Feed only after most of the previous food is disappearing, rotate the feeding location, and keep bedding as damp as a wrung-out sponge. Add dry paper if the bin becomes wet. Harvest castings when the lower material is dark and uniform, then return worms and unfinished bedding.
Common problems to avoid
Odor and flies usually mean overfeeding or exposed food. Avoid meat, dairy, oily food, pet waste, and large amounts of citrus or onion. A worm bin is a living system, so freezing garages and hot balconies are unsuitable even when the container itself fits.