Vermicomposting, the simple way

For me, composting is mostly a sustainable and convenient way to dispose of food scraps. Sure, it's good fertilizer but the amount of compost we generate doesn't put a dent into what we'd need to fertilize the gardens. When I need a lot of compost, our neighbor drops off a tractor bucket or composted manure, or I order some. 

When we first moved here, I started a compost bin outside. It was okay but a bit of a hassle to walk out and dump scraps, and we often procrastinated (especially in the wintertime) and ended up with a slimy bucket of scraps on the counter or even worse, fruit flies. Ever since I switched to vermicomposting (worm composting), those worries are over. I keep my worm bin next to the kitchen so it's easy to throw food scraps in as we go.

To start vermicomposting, you need worms (you can order them online) and a worm farm or bin. There are many specialty bins available online, but, I'd rather make my own. I used two identical rubbermaid bins, one nested into the other. I drilled many, many holes in the inner bin, so that any excess liquid would drain out into the outer bin.

Once my worms arrived, I put them in the inner bin along with some moistened bedding. I used coco coir (ordered at the same time as my worms) but there are many options. 

Once the compost is underway, I always keep about 3-6 inches of dry, shredded newspaper on top. I used to shred the paper by hand but I now use a paper shredder. This helps created a dark but airy environment for the worms, control humidity, and prevent fruit flies. The worms also gradually munch on it.

Whenever I have food scraps, I lift up the shredded newspaper and add the food scraps in between the compost and the newspaper shreds. 

I don't have a lid on my bin. At first I did, but the lid made the bin too humid. The walls of the bins were covered in water and that made it very appealing for the worms to crawl up the sides and escape from the bin at night (they don't like light, so they don't escape during the daytime). Once outside the bin they would dry up and die. Not good! Once I stopped putting a lid on it, problem solved. The newspaper keeps it dark enough for them to be happy in the compost. There are many theories online about keeping the newspaper moist, but, I find that the lowest layer of newspaper gets moist just from absorbing moisture from the food scraps and compost. The top stays dry and the worms stay away from it. 

Once in a while, I throw in some eggshells grinded up in my food processor or mortar and pestle. The worms apparently need to eat this "grit" to help them grind up the food they eat.

It's important not to overwhelm the bin with food scraps - the worms can only process so much. The worm population will adapt to the quantity of food you generate. However, in my case, when it's time to put up a lot of food (canning season), I have too much waste all of a sudden - in that case I put all the excess in my outdoor compost bin. But the rest of the year, the worm bin in sufficient.

Every 1-2 years I harvest the compost. I have not found an easy way to do this. I used my 3D printer to print 3 sieves with holes of various sizes, that I designed to mimic the fabric screens people buy to make sieves. That allowed me to catch all the unprocessed bits of food (which I returned to the bin).  But ultimately, I also need to do some hand separation of the worms and the compost. Since they run away from light, it's possible to scoop up the top layer of compost which will be worm less. By the time you put that layer into a bucket, the worms will have gone deeper and you can repeat that process. 

The worms need very little attention. Just topping up the shredded newspaper when it gets low. When we leave on vacation for a few weeks they don't need any special attention (don't overfeed them just before leaving - that's a recipe for fruit flies! Just give them the normal amount of food. They will keep busy processing leftover scraps and newspaper until you return. 

The 3D printed sieves I designed and printed