Preparation of Vermicompost

Overview

The preparation of vermicompost is mostly a matter of letting the worms do the work. You set up the bin and gradually add kitchen scraps, while the worms recycle them. The bedding and food scraps they consume pass through their gut to become castings--rich organic material with an earthy smell that looks like fine-textured soil. Vermicompost is superior to regular compost in nutrient density. Use it to enrich garden soil, mulch, pot plants or top-dress your lawn.

Step 1

Place shredded cardboard or newspaper in a washbasin. Fill the basin with enough water to cover the bedding and let it stand until it has absorbed as much water as possible. This may take about 2 hours for newspaper, but several more for cardboard.

Step 2

Wring or squeeze out the bedding to remove excess water, until the material is about as wet as a wrung-out dishcloth.

Step 3

Set the worm bin up on bricks or blocks. Fill it three quarters full of the moistened bedding and lift it gently to create air spaces for the worms. Allow the bin with bedding to sit for 3 to 4 days before adding worms.

Step 4

Scatter the worms on top of the bedding. They'll crawl down into the bedding in short order because they do not like light. Add a handful or two of sand to the bin. (Since these worms have a gizzard, they benefit from having some sand to aid the digestive process.) Cover the bin.

Step 5

Begin adding kitchen scraps gradually. Pull the bedding back in one area, dump scraps in and cover them up with at least an inch of bedding. Put each day's scraps in a slightly different place and cover them with bedding.

Step 6

Keep the bin damp and dark. Monitor the bedding and spray it with water when it becomes dry.

Step 7

Add food scraps for about 2 to 3 months. Once the bedding has all been consumed, harvest the vermicompost.

Step 8

Move the finished compost to one side of the bin. Fill the other side with fresh wet bedding and a few handfuls of food scraps.

Step 9

Cover the bin and allow the worms to move out of the finished compost into the new bedding with fresh food waste.

Step 10

Remove the finished compost from the bin the following day. Replenish the bin with additional moistened bedding so it is again about three quarters full.

Things You'll Need

  • Bedding (shredded corrugated cardboard and/or newspaper)
  • Washbasin
  • Worm bin
  • Bricks
  • 2 lbs. redworms or brandling worms per 4 cubic feet of bin space
  • Sand
  • Fruit and vegetable kitchen scraps
  • Clean spray bottle

References

  • New Mexico State University: Vermicomposting
  • University of Nebraska Extension: Vermicomposting

Who Can Help

  • Washington State University: Cheap and Easy Worm Bin
Keywords: make vermicompost, worm castings, food scraps

About this Author

Ann Wolters, who has been a freelance writer, consultant, and writing coach for the past year and a half, has had her writing published in "The Saint Paul Almanac," and in magazines such as "Inventing Tomorrow" and "Frontiers." She earned a master’s degree in English as a second language from the University of Minnesota and taught English as a foreign language for nearly seven years.