The flow is like this: We produce green waste almost daily in the form of kitchen and garden scraps, news papers, and grass clippings. We can do one of 3 things with this green waste: throw it in the garbage and eventually the landfill (more on this later), throw it on the compost heap for a couple of months, OR you can feed it to certain types of worms, which speed up and enhance the composting process! So let's look at the third and, in my opinion, best option! I'll show you what worms to use and how to set up your own vermicomposter that is super easy!
The type of worm is very important in vermicomposting. Most of us have seen these juicy little suckers in our garden at night, hence their name: Night Crawler.
Although important for soil aeration, these guys pretty much suck at composting. Sorry guys :(
The worm of choice for composters all over the world is known as (creatively) the redworm. They are a litter-swelling species (meaning they live in piles of leaves and other organic material rather than in the soil), very tolerant of temperature changes, reproduce very rapidly, and thrive in the compost bin environment.
Be sure to check with your local department of agriculture before purchasing worms, though, because many states have strict laws and quarantines regarding illegal worm species!
Redworms, and plenty of them! Dinner is served.
After a few weeks inside the bin, you'll have this lovely soil called worm castings which is essentially worm poo. It has a great structure and texture, allowing for proper drainage and water retention, and has a C:N ratio of around 15:1 (email me if you want an explanation of Carbon to Nitrogen ratios in soil and compost and why it is so important). Note the little yellow and red worm eggs on top of this pile. Each one has about 4 little worms in it.
Here's how Western Worm produces their castings: in 3 gallon shrub pails, all stacked in a warehouse:
Most of us don't have the space for an operation of that size, so I'm going to show you how to set up a smaller system in your home (yes, I said IN):
The University of Hawaii suggests adding 1-2 cups of kitchen scraps and then waiting for 2 weeks before adding more. This will let the worms get used to their new home without feeling too overwhelmed with food to eat. Put the lid on and you're done! As the bin fills with castings, get the other bin ready (the one with holes in the bottom) with a new layer of bedding and table scraps. Place that bin directly in the casting bin and give the worms a couple of weeks to migrate up through the holes into the new bin. You can then remove the castings bin and use the poo for your garden. Rinse. Repeat.
So how is this sustainable Ag? Simply put, worms speed up the composting process. What takes several months in your compost heap can take only weeks in a properly-managed worm bin. Vermicomposting can be done in urban environments, where the alternative is throwing it in the landfill:
According to the EPA, (http://www.epa.gov/methane/sources.html) roughly 30% of the methane in our atmosphere comes from compostable material in landfills and in manure. If large vermicomposters were used to process these materials, which would be hella easy, these greenhouse gas emissions would be greatly reduced, if not eliminated all together. So, first use: waste management!
Secondly, many areas of the world that suffer from starvation also have very poor soil. Vermiculture is a way of taking garbage, human and animal wastes, and food scraps and turning it into a usable soil that can be used to grow food for millions of people.
Third, in the home, it saves you from having to buy expensive topsoil additives, and can be used as an organic fertilizer (it has fungicidal, parisiticidal, and nemotodicidal properties as well!) to help you grow your own food locally and if you're ambitious, can supply you with plenty of extra to share at the farmers market! Happy Worming!