Adding worms to my first worm bin!

Every Friday at Kosmix all 60 of us sit down to have lunch together, and someone from the company gives a presentation.  The talk can be about anything—people share their projects, hobbies, work and adventures.  We’ve had discussions about everything from beekeeping to the physics of absolute zero to volunteer projects in African orphanages.  The folks at Komix are an eclectic bunch, and the sessions are always entertaining.  So today, I decided to haul in my Rubbermaid bin and talk about a project I’ve been experimenting with for the last few months – vermicomposting!

In case you didn’t know, compost is a fertilizer material that you can make from everyday food scraps. Adding it to potting soil gives a lot of nutrients to your plants, which is great especially if you have a garden! Vermicomposting is where you create compost by using worms to break down the material, and has a lot of benefits over the traditional compost pile method. The biggest one for me was time – cold compost piles take a long time before you can harvest the compost (anywhere from 13 to 18 months) whereas vermicomposting takes around 3 – 6 months. Another is location convenience, since I can put my worm bin in the garage where it’s easy for me to access. Plus in addition to reducing my food waste, I like to think of it as an extremely cool science experiment!

So what can you compost? You can compost a variety of “green” materials such as fruit/vegetable scraps, egg shells, tea leaves and coffee grounds. You also should mix in “brown” materials such as newspapers, junk mail (not glossy!), dead leaves, and cardboard. You can’t compost meat/fat, oily foods, dairy, or grains – the worms can’t/won’t break these down, although in the case of grains I hear it varies by type.

Set-up is actually really easy. All you need is two bins (one with holes drilled all around it) that fit inside each other, bedding material (shredded brown materials as listed above) and of course worms! Moisten the bedding until it’s like a wrung out sponge, and place about 4 inches worth inside the bin with holes in it. Add worms and add another couple inches of bedding on top. Voila! Now whenever you want to “feed” your worms, you pull back that upper layer of bedding, place your scraps, and cover it up again. You can harvest your compost when most of the food/bedding is gone, and has been replaced with a brown coffee-ground like material. An easy way to harvest is to set up another bin with holes in it, place that on top of the old bin and put all future scraps in that one. Then the worms will slowly migrate over through the holes in the new bin.

I hope this post intrigues a few minds and starts some new worm bins! In case you are interested in learning more, here are a few sites that have great articles and more details on how to get started.

• Craftzine – How to Make a Worm Composting Bin
  – a more detailed but still simple tutorial on how to start a bin
• Recycle Works – Worm Composting Basics – vermicomposting information and composting classes in San Mateo County
• Red Worm Composting – basics and articles about a variety of ways to harvest compost

Please feel free to ask questions and share your experiences in the comments!