Friday, December 11, 2009

Vermicomposting, Part I

A few weeks ago I had the chance to attend the Urban Homesteaders' League's Vermicomposting Extravaganza workshop with Ryan Gray. And last Saturday, I finally received my worms! Before the workshop I didn't realize how easy and simple vermicomposting actually is, and I am very excited to start!

is a method using earthworms to turn food/organic waste into nutrient-rich compost. Vermicompost contains worm castings, bedding materials, and organic wastes at various stages of decomposition, and contains worms at various stages of development and other microorganisms associated with the composting process (2). Worm castings, or worm poop, is the end product formed after the earthworms break down organic materials. Worm castings contains many beneficial microbes and nutrients and is a very nutrient-rich plant fertilizer (2).
Vermicomposting is perfect for those living in urban areas. And if you are composting correctly, the compost bin shouldn't even smell at all!

What do you need to begin vermicomposting?
  • A container with a lid
  • Bedding material, such as shredded newspaper. Ink should be soy-based!
  • Moisture (ex. water in a spray bottle)
  • Redworms aka red wigglers or Eisenia fetida (Get them from a friend, or order them online, such as from WormWoman).
Shredding the newspaper
Photo courtesy of Lisa Gross
  • Drill ventilation holes around the top sides of the bin and on the lid. (The worms need oxygen to breathe. And drill small holes so your worms don't escape!)
Drilling the ventilation holes
Photo courtesy of Lisa Gross

It's all about teamwork
Photo courtesy of Lisa Gross
  • Completely FILL your bin with bedding, such as shredded newspaper. Ryan recommends to shred the newspaper thin, around ¼ to ½ inch thick.
  • Worms breathe through their skin, so the bedding needs to be moist. Spray the newspaper so that it's "fluffy and damp," but not soaking. You don't want your worms to drown!

  • Add the redworms and some food scraps to the bottom of your bin and let them get to work!
  • Be careful about OVERFEEDING your worms. You want to avoid the odors of rotting food, and you want to give the worms enough room to move around as they get adjusted in their new home!
  • Once your worms begin reproducing and become assimilated to their environment, you can begin feeding them more. Have excess food scraps? Refrigerate or freeze them for later!
  • You can add more bedding if it gets low, and be cautious that the bin doesn't become too moist.
  • Every few months, harvest your fertilizer! One easy way to do this is to put food scraps on one side of your bin to attract the majority of your worms (or you can also do this on the ground on top of some spread out newspaper/plastic). Once you've gathered /separated your compost and picked out any extra worms hiding inside, add some new bedding to your bin and you can begin the process all over again!
Sources: Ryan, myself, here, and here

A Word About Temperature:
  • Redworms are happiest at ~60-75 degrees F, but they can survive at temperatures of 50-80 degrees F.
DO compost
  • Raw vegetable products
  • PLAIN, cooked vegetable products (no oil added, etc.)
  • Eggshells (it's recommend to rinse them first)
  • Cereals and oatmeal
  • Coffee grounds
  • Tea bags
  • Beans
  • Newspaper (with soy-based ink!)
DON'T compost
  • Meat, chicken, dairy, or fish products
  • Oily/greasy foods
  • Non-citrus fruits (they are completely compostable, but they may smell more and attract more flies)
  • Citrus fruits- at a minimum, or just avoid them!
  • Bread- at a minimum
  • The smaller the food scraps/the larger the surface area of your food, the easier it will be for the worms to break it down! They "lick" rather than chew.
Some of Ryan's Recommended Sources:
-Fun fact: Worms eat over half their body weight in organic matter a day.

What to do with your food scraps that aren't good for your redworms, or what to do if you aren't up for vermicomposting just yet?
Vermicomposting is a wonderful way to recycle your food and to create some very healthy and nutrient-rich soil!

Have questions for Ryan about vermicomposting? Contact him at compostboy[at]

Thanks to Ryan for a great workshop, great information, and for breaking down vermicomposting into a simple and easy process. Thanks to Erik Zornik as well, who also provided some great tips. And of course, thanks to the Urban Homesteaders' League for hosting this workshop. Look forward to an upcoming blog post on Worm Updates in the next few weeks!

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