How to Start Worm Composting? | Your First Indoor Worm Bin

For the full breakdown, see our best Earthworms For Composting guide.

Worm composting (vermicomposting) is the easiest way to turn vegetable peels and coffee grounds into dark, crumbly fertilizer without a backyard pile. The whole system fits under a sink or in a closet, produces no smell when maintained correctly, and needs attention only once a week or so. You need four things to begin: a ventilated container, bedding, food scraps, and red worms — not the common earthworms from your garden, but a specific composting species.

What Kind of Worms Do I Need for Composting?

Only red worms — Eisenia fetida, commonly called red wigglers — will thrive in a contained bin. Regular garden earthworms need deep soil and die in a closed bin. Red wigglers breathe differently, tolerate crowding, and eat voraciously. You can order them by the pound online or find them at garden centers that sell composting supplies. One pound handles a standard 2-foot-by-2-foot bin comfortably; two pounds works for a larger 2-foot-by-3-foot setup.

Setting Up the Bin: The Step-by-Step

A 10-gallon plastic tote with a lid works perfectly for most households. Follow this sequence once, then add food scraps on a weekly schedule.

Prepare the container. Drill a 1-inch hole about 2 inches from the top on one side, and another matching hole on the opposite side for airflow. Near the bottom corners of the same sides, drill four 1/8-inch drainage holes. Line each hole with a small square of fiberglass window screening (held in place with silicone or a hot-glue dab) to keep worms from escaping. If you use a wooden bin instead, line the bottom and sides with plastic sheeting to protect the wood from moisture.

Add the bedding. Shred plain black-and-white newspaper or corrugated cardboard into strips about 1 inch wide. Fill the bin about three-quarters full with the strips. Soak them in a bucket of water for a few minutes, then squeeze handfuls until they barely drip — the correct moisture level feels like a wrung-out sponge. Fluff the damp strips back into the bin.

Add the worms and food. Sprinkle 2 to 4 cups of ordinary garden soil over the bedding (this provides grit that helps worms digest). Place the red wigglers on top, close the lid, and leave the bin alone for one full week — the worms need time to burrow down and acclimate before you start feeding. After that week, bury a shallow layer of kitchen scraps (about 1/4 to 1/2 pound of food per pound of worms) under the bedding. Cover the food with dry shredded newspaper or leaves so fruit flies cannot reach it. Feed again once most of the previous food has disappeared, usually after five to seven days.

Where to Keep Your Worm Bin and What to Avoid Feeding

Place the bin somewhere between 50°F and 80°F (13°C to 25°C), out of direct sunlight, in a low-traffic area such as under a kitchen sink, in a basement, or inside a closet. The RHS recommends covering the initial bedding with no more than 8 to 10cm (3 to 4 inches) of kitchen waste when you start feeding. The Cornell method suggests leaving the lid slightly ajar for airflow; a closed lid is fine as long as the side ventilation holes stay clear.

Red wigglers can eat most plant-based kitchen scraps, but avoid citrus peels (the acidity harms them), meat, dairy, oily foods, and onion or garlic in large amounts. Coffee grounds are excellent — worms love them — but top each layer of wet scraps with a thin layer of dry material like shredded leaves or paper to maintain the sponge-like moisture level. If the bedding starts packing down or smelling sour, you are overfeeding; cut back by half and stir the bedding gently to reintroduce air.

How to Harvest the Finished Compost

After three to six months the bedding will have transformed into dark, earthy-smelling castings. The easiest harvest method is called migration: push all the bin contents to one side, add fresh bedding and food to the empty side, and stop feeding the old side for two weeks. The worms migrate to the new food, leaving the finished compost mostly worm-free on the other side. Scoop out the dark castings and use them as a soil amendment — mix a thin layer into potting soil or sprinkle around garden plants. A mature bin produces usable castings continuously; you can harvest every few months without ever fully emptying the bin.