How to Keep Compost Worms


Composters who have small backyards or live in high-rise apartments often opt to discard their kitchen scraps with the help of compost worms. Rather than throw food scraps, such as banana peels and leftover carrots, in your trash can or down your garbage disposal, you can feed them to your compost worms, which consume and process the old food into nutrient-dense humus. However, don't just toss your worms into a bin and expect them to fend for themselves. Keeping compost worms successfully requires careful preparation and regular maintenance.

Step 1

Weigh your household food scraps each day for one full week. Tally up the total amount of waste to determine how many pounds of worms you'll need to process it. Plan to get approximately 1 lb. of worms (about 1,000 worms) to eat up to ½ lb. of food waste each day.

Step 2

Find a plastic bin that measures 12 to 14 inches tall. Allow 1 square foot of surface area for each pound of weekly food waste. For example, if your household produces 4 lbs. of food scraps each week, then use a plastic bin that provides 4 square feet of surface area, such as a 2-by-2 foot bin.

Step 3

Drill four holes per square foot in the bottom of the bin for drainage. Use a 3/8-inch bit and space the holes at equal distances from each other. Drill a single row of ventilation holes around the circumference of the bin; locate the row of holes 2 inches from the top edge of the bin and drill them in 1-inch increments.

Step 4

Sprinkle 3 inches of finely shredded newspaper across the bottom of the bin for bedding; dampen it with a water-filled spray bottle, adding enough moisture to make the newspaper about as wet as a wrung-out sponge. Add additional moist bedding in 3-inch increments until the bin is approximately three quarters full.

Step 5

Put your compost worms in the bedding and cover the bin loosely with a sheet of cardboard. Place the bin in a warm, dry location, such as your basement or the cabinet beneath your kitchen sink.

Step 6

Feed your compost worms once weekly; Cover the food with 3 to 4 inches of fresh bedding to minimize possible odors. Stick with mild food scraps, such as fruit and vegetable waste; avoid smelly foods, particularly milk products, meat and bones, which may attract rodents and other pests. Sprinkle finely crushed eggshells in the bin once monthly to provide grit, which helps the worms digest food more quickly, according to Loren Nancarrow, co-author of "The Worm Book."

Step 7

Harvest finished worm compost 10 to 12 weeks after you start feeding your worms. Shove bedding to one side of the bin; fill the empty side of the bin with fresh, damp bedding. Leave the worms alone for 2 to 3 days so they can migrate to the fresh bedding. Scoop out the old bedding with a hand trowel, checking each scoop to ensure that no worms are present in it. Let the mature compost sit in a plastic bucket for 4 to 8 weeks to finish breaking down before you apply it to your plant soil.

Things You'll Need

  • Kitchen scale
  • Plastic bin
  • Drill with 3/8-inch bit
  • Newspaper
  • Water-filled spray bottle
  • Compost worms
  • Sheet of cardboard
  • Food scraps
  • Crushed eggshells
  • Hand trowel
  • Plastic bucket


  • "The Worm Book"; Loren Nancarrow & Janet Hogan Smith; 1998
  • Canada's Office of Urban Agriculture: Worm Composting
Keywords: compost worms, how to compost, keeping red worms

About this Author

Regan Hennessy has been writing professionally for 11 years. A freelance copywriter and certified teacher, Hennessy specializes in the areas of parenting, health, education, agriculture and personal finance. During her time with Demand Studios, Hennessy has produced content for Ehow, Answerbag and Travels. Hennessy graduated from Lycoming College with a Bachelor of Arts degree in English.