How to Buy Composting Worms


Composting worms transform food scraps into nutrient-rich humus for you to use to enrich the soil in your gardens and potted plants. Whether you're tight on space and want just enough worms for a small plastic bin or you plan on starting a multi-bin worm composting system, the worms you purchase play an essential role in determining the success of your compost bin. Generally sold by the pound, composting worms come in various sizes and species, so make sure you know what to look for before you set out in search of your wiggly composting machines. Prices vary, depending upon the worm species and your worm supplier, but as a general rule, plan on spending approximately $25 to $35 per pound of composting worms.

Step 1

Weigh the amount of food waste that your household produces in one week to determine how many pounds of red worms you'll need to purchase. Plan on getting 1 pound of worms to process up to half a pound of food scraps daily; for example, if your household produce 7 pounds of food waste each week, you'll want to purchase 2 pounds of red worms, which translates to approximately 2000 individual, adult-sized worms.

Step 2

Gather a list of possible worm suppliers, which may include other worm composters, bait shops and online worm farms. Ask friends and other worm composters for recommendations. Look for a worm supplier that provides Eisenia fetida, a common native compost worm species that has a hearty appetite for food scraps and a reputation for easy maintenance.

Step 3

Protect yourself from accidentally purchasing invasive worm species by looking for a worm supplier that lists and sells worms by their species rather than common names (such as red wriggler or manure worm), as recommended by Cathy Cromell, certified master gardener and author of the book "Composting for Dummies." Avoid backyard worm farms and worm suppliers that mix different worm species together or don't know the exact worm species present in their bins.

Step 4

Prepare your worm bin ahead of time by filling it three-quarters full of shredded newspaper. Moisten the newspaper bedding with water and gently tip your new composting worms onto the top of the wet bedding. Cover your bin loosely with a piece of cardboard and keep it in a warm, dry location that generally remains between 55 and 77 degrees F., as recommended by Loren Nancarrow, coauthor of "The Worm Book."

Tips and Warnings

  • Avoid purchasing non-native compost worm species, such as Lumbricus rubellus, as these worms' insatiable appetite for leaf litter may contribute to a disruption of the nutrient cycle in American forests, according to Cromell.

Things You'll Need

  • Scale
  • Food scraps
  • Paper and pencil
  • Worm bin
  • Shredded newspaper
  • Water
  • Piece of cardboard


  • "Composting for Dummies"; Cathy Cromell; 2010
  • "The Worm Book"; Loren Nancarrow & Janet Hogan Taylor; 1998
Keywords: buying compost worms, compost worm cost, buying 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.