Worm Bin: Make Your Own Indoor Composter

Near the top of the box, drill 2 rows of 1/16" holes. In the lid, drill 30 or so evenly spaced 1/16" holes.

• Shred newspaper or office paper. Use a paper shredder if you can, or cut the newspaper into roughly 1" strips with scissors.
• Moisten the shredded paper with water and let it soak in for a few minutes. This can be done in a separate bucket to reduce the mess. The paper should be damp but not soggy; squeeze out any excess water and then put it in the plastic box. Fluff it up so that there is air between the paper, and fill the plastic box about ⅔ full.
• Add the soil to the plastic box.

With the trowel (or your hand), dig halfway through the bedding in the middle of the box. Tuck your red wigglers into their nice, moist bed and then cover them with the bedding.

• Use tape and popsicle sticks to make an X-shaped marker, or find some other object to use as a marker. You’ll put it on the bedding over the scraps, so you can identify where you placed the food most recently.
• Dig a hole in the bedding material in a corner of the plastic box. Place a small amount of kitchen scraps in the hole, cover it with bedding, and then place the marker on top. Worms like any fruit, vegetable, or grain/bread. They also like coffee grounds and filters, tea bags, crushed eggshells — stuff you usually put down the garbage disposal.
• Treat your worms like they’re vegan — don’t give them meat, fish, or dairy. They can eat these foods, but the bin will get smelly and attract pests. Also avoid oils, salt, and animal poop, and go easy on the citrus as it contains limonene, a compound toxic to worms.
• It takes a while for the worms to get going, so don’t be too impatient. As they multiply, they’ll consume your kitchen scraps faster.
• After a few days, check the bin. If the kitchen scraps are mostly gone, put another batch of scraps in. Put them to the right of the first batch, and then move your marker over to cover the new spot. Continue like this clockwise around your new compost box.

• Your new worm composter can live in many places in your home: under the sink, in the laundry or storage room, even on the balcony. Your chosen spot should have good ventilation, easy access to collect the compost tea, and a suitable temperature. The best temperature for worms is between 55°–77°F year round, so make sure they won’t freeze or fry.
• Place the second lid under your new worm bin to collect the drips that will become compost tea.

• Moisture: If the contents seem too dry, add a little water. If too wet, add shredded newspaper.
• Smell: The worm composter can become anaerobic (deprived of oxygen) if there is more food than the worms can eat quickly. If that happens, don’t add scraps for a week or so. Give the worms a chance to catch up.
• Also add more bedding (damp, shredded papers). Make sure there are enough ventilation holes in the container, and fresh air around the container. Fluff the bedding. If you leave it alone awhile, the situation should correct itself.
• Fruit flies: Make sure that food is buried and covered with bedding to avoid fruit flies arriving.
• Worms dying or escaping: Check the moisture content of the bin: if it’s too wet, add bedding; if too dry, add water. If the contents look brown all over, then it’s time to harvest your new soil.
• Tea tray: If the tray has a lot of brown sludge in it, scoop it into your watering can. Fill the can with water and let it steep for a day, stirring occasionally. Then water your plants with this highly nutritious compost tea fertilizer.
• Harvest time: When all the bedding is gone and your composter smells like a fresh forest (usually after 3–5 months) it’s time to harvest. It’s better to harvest too early than too late, which can kill your worms. Any bits of food left over can be put back into the next worm composter iteration.

• Quick and messy method: To separate the worms from the compost, empty the contents of the worm composter onto a tarp or old plastic tablecloth. Worms hate light and will wiggle into the pile. Wait a few minutes.
• Then with your trowel or your hands, remove the top layer of the compost pile until you see worms. Then wait again, be patient, and continue removing the compost. Repeat until there are lots of worms in a small pile. All the worms can go into the next iteration of the compost box, or half can start another compost box.
• Slow and neat method: Make a second, identical compost bin by repeating Steps 1, 2, and 3. Take the lid off your first, full composter, and place the second bin directly on the compost surface of the first. Then repeat Step 5, putting kitchen scraps in the second box, and put the lid on the second box. In 1–2 months, most of the worms will have moved upstairs to find the food there. The first (bottom) compost box will contain mostly vermicompost.
• Red wigglers are not native to North America. They are an invasive species in many areas, so don’t dump worm-containing compost in natural areas; this could end up displacing the native worms.