Even if you only have a small garden, taking time to build a worm composting bin will pay you back with plenty of nutrient-rich compost for your soi—and will do double-duty by taking care of kitchen scraps.
Step 1: Gather Materials
- Plastic box or bucket, no more than 24 inches tall (a 5-gallon bucket is ideal)
- Enough shredded cardboard or newspaper to fill your box or bucket
- 2 cups of potting soil or peat moss
- Piece of canvas or a burlap sack, big enough to cover your box or bucket
- Plastic plate or tarp to set under the bucket
- Two bricks
Step 2: Prepare the Bin
Wash your box or bucket first, and rinse it thoroughly. Fill your box or bucket with clean water, and let stand for a day or so to soak away any traces of chemicals or soap that may be harmful to your worms.
Empty your box or bucket. Drill several holes in the sides and bottom to allow for drainage and ventilation.
Step 3: Find a Place for the Bin
Keep your compost bin in a shady spot, where the temperature will stay between 50 and 80 degrees. If you live in an area with cold winters, you will have to find a space to move your bin in the winter. Place the plastic plate or tarp in the spot you have chosen for your bin.
Step 4: Build Your Worms' Habitat
Fill the box or bucket with shredded cardboard or newspaper. Cover with the potting soil or peat moss. Set the bricks on top of the plastic plate or tarp, and rest the bin on top of the bricks; this will keep the bin off the ground and let air circulate under the bottom.
Water the contents of your bin until the soil is thoroughly moist. Let the paper soak for at least a day so it can absorb as much water as possible.
Step 5: Add Worms
You will need about a pound of worms to start. For the healthiest worms, purchase them from a garden shop or bait shop instead of digging them yourself. Add the worms to your bin, and cover the bin loosely with the canvas or the burlap sack.
Step 6: Maintain Your Bin
Water the surface of your bin lightly every other day. Feed your worms at least once a week—preferably more—with kitchen scraps like fruit or vegetable peels, bread or coffee filters with coffee grounds. However, do not feed your worms meat, eggs, or dairy products.
To feed your worms, lightly bury the scraps inside the bin. Once a month, or as needed, add more shredded cardboard or paper to fill the bin back up.
Step 7: Harvest Your Compost
Within a month, you will notice a soil-like substance collecting in your bin. This is the compost, which the worms produce by digesting the kitchen scraps. Carefully remove this compost without digging up the worms too much, and use it as rich fertilizer for your garden and houseplants.