How to Age Vermicompost


Vermicompost or worm castings, is created when organic matter passes through a worm's digestive system and becomes a highly potent organic soil amendment. Vermicompost has a high concentration of nitrogen, calcium, magnesium, potash, and other necessary microorganisms for healthy plant growth. The National Sustainable Agriculture Information Service describes vermicompost as "biologically active as well as containing plant hormones which can provide other advantages." It takes two to three months to make a batch of vermicompost from food scraps, yard trimmings, newspapers or straw, according to University of New Mexico Extension. The last stage of the process is aging the vermicompost. Aging increases the amount of worm castings in the final product.

The Aging Process

Step 1

Check the vermicompost bin to see that the worms have eaten the majority of the food scraps provided for them. The mixture will have worm castings, small amounts of decomposed matter and partially decomposed bedding materials. The worms convert the remaining material to castings if new food is not available, according to Canadian environmental organization Green Calgary. Stop providing them with new food.

Step 2

Push the old bedding with worms and partially decomposed materials to one side of the worm bin. Add new bedding and new food to the vacant side of the bin. The new bedding consists of shredded newspapers, non-slick paper, moist peat moss, cut-up yard clippings and food scraps. Keep the bedding moist but not soggy. New food is put in the vacant side of the bin to entice the worms into it and away from the finished vermicompost.

Step 3

Wait two to three weeks until the majority of worms have migrated to the new bedding area. Remove the vermicompost, including any remaining worms and old bedding, and place in a clean container to continue aging, advises Green Calgary. The remaining worms will eat any partially decomposed bedding and food still in the vermicompost in about three months, according to the organization. The aged vermicompost is now a highly concentrated plant food ready to use in the garden.

Tips and Warnings

  • Soak peat moss 24 hours before use as a bedding material. Put food scraps into different areas of the bedding each time to keep food scraps from accumulating. Do not overload the worm bin with food scraps because foul odors will develop.

Things You'll Need

  • Worm bin
  • Shredded newspapers
  • Food scraps
  • Yard clippings
  • Rubber gloves


  • New Mexico State University Extension: Vermicomposting
  • Green Calgary: Harvesting Vermicompost
  • National Sustainable Agriculture Information Service: Worms for Composting

Who Can Help

  • Red Worm Composting: Getting Started
  • Green Calgary: Vermicomposting
Keywords: vermiculture, worm compost, vermicompost

About this Author

Joan Norton, M.A., is a licensed psychotherapist and professional writer in the field of women's spirituality. She blogs and has two published books on the subject of Mary Magdalene; "14 Steps To Awaken The Sacred Feminine:Women in the Circle of Mary Magdalene," and "The Mary Magdalene Within."