Apartment dwellers and city residents often lack the outdoor space necessary to produce nutrient-dense compost using traditional composting methods, such as piles and tumblers. With the help of compost worms, you can convert food scraps into mature compost in a space as small as a five-gallon bucket, according to Mike McGrath, compost expert and author of “Mike McGrath’s Book of Compost.” Recycle a used five-gallon bucket or purchase a new one from your local home improvement center. Look for compost worms, also called red worms, at a brick-and-mortar fish bait shop or pet store or purchase them from an online worm farm; opt for a native red worm species, such as Eisenia fetida.
Invert your five-gallon bucket on a flat surface. Drill six to eight evenly spaced holes in the bottom of the bucket with a 3/8-inch bit. Place the bucket upright and drill a single row of ventilation holes 2 to 3 inches from the top edge of the bucket. Space the ventilation holes in 2-inch increments.
Shred newspaper into small pieces and layer it in the bottom of the bucket in 3-inch increments. Spray each layer of the shredded newspaper with water to dampen it. Stop adding newspaper when the bucket is approximately 3/4 full of the moist bedding.
Dump approximately 1/3 lb. of red worms (approximately 330 worms) gently on top of the bedding. Cover the top of the bucket with a piece of cardboard. Place the bucket in a warm, dark area of your home, such as the cupboard beneath your kitchen sink.
Give your worms mild food scraps, such as vegetable peels and fruit waste, once or twice weekly, burying the food beneath 3 to 4 inches of bedding. Check the moisture level of the bedding each time you feed your worms; ideally, it should remain about as damp as a wrung-out sponge to keep the worms from drying out. Add extra water, if necessary.
Avoid smelly food waste, such as dairy products and meat, since they often cause strong odors and attract pests. Sprinkle crushed eggshells on top of the bedding once or twice monthly to give your red worms grit, which helps them digest the food scraps more quickly, according to Janet Hogan Taylor, coauthor of “The Worm Book.”
Look for signs of finished compost approximately 10 to 12 weeks after starting your compost bucket; the materials in the bin should have decreased in volume and look like clumps of brown soil. Dump the contents of the bucket on a large plastic tarpaulin in a sunny location, such as a patio.
Scoop finished compost from the pile with a trowel, removing it gradually until you have only your worms and a small heap of mature compost remaining. Place the worms and the bit of mature compost into a freshly bedded five-gallon bucket and begin the composting process again.