Several people have asked me how we manage a very productive vegetable garden; so I’ve written this post as a brief description of one aspect our our approach - vermiculture.
One of our overarching family goals is sustainable living. It’s basically about leaving a small footprint. A practical component of this philosophical stance is dealing with food waste. We deal with kitchen waste with a combination of bokashi composting and vermicomposting (also known as vermiculture) It’s not for the faint-of-heart and some are horrified to learn that I keep thousands - possibly hundreds of thousands - of worms in our basement. But some have asked me to describe our process; so this article is meant just to document it. There is a lot of art and science to vermiculture and this is not meant to be a definitive guide to vermiculture.
Worms can consume food scraps and other organic material, turning it into worm castings (aka “poop”) that enriches garden soil. We raise composting worms as part of our strategy to reduce waste and to enrich the organic content of our garden.
It’s important to distinguish between two types of worms:
- Composting worms
The worms that you find when digging in the garden or that you see on the sidewalk after a rainfall, are not composting worms. These earthworms do consume organic material but they live in deep burrows and do not tolerate the high living density that compost worms do. Basically, they are loners. Composting worms naturally live together in much higher density, just under the veneer of leaf litter and can be voracious consumers of organic material. So the bottom line is that you cannot just pick up some earthworms off the sidewalk and start a vermiculture operation. For the most part, you have to purchase them.
Our composting worms
We play host to three different types of composting worms:
- Red wrigglers (Eisenia foetida) - this is the most common “workhorse” of the vermiculture world and are the easiest to purchase. They are like the Dodge Stratus of the worm world. Commonplace and not likely to win any speed records, but they get the job done.
- African nightcrawlers (Eudrilus eugeniae) - these are fast composters and not as easy to find commercially. They are a much larger worm than the red wriggler; and they are fairly picky about temperatures. They cannot tolerate cold temperatures like the Eisenia foetida but they work fast and furiously, consuming huge amounts of organic material. If the red wriggler is the Dodge Stratus, these are the Ferrari’s of the the vermiculture world.
- Some unknown worm - I harvested a bunch of worms from an outdoor compost pile. Despite my best efforts, I have never identified exactly what they are.
Worm husbandry - our approach
Typically, after fermentation, bokashi compost is buried in garden soil, where soil microorganisms complete the decomposition quickly. However, I discovered that this pre-compost is also a fantastic food source for worms in a worm bin. The acidity of the bokashi compost requires a bit of dolomitic lime to balance the pH for the worms. We also limit the amount of bokashi compost to what the worms can process in 10-14 days to maintain their health. An added bonus is the heat produced during the bokashi breakdown, which benefits our worms living in a cold basement.
Another critical aspect of successful worm composting is bedding, which should be about 80% of the bin’s content. Bedding, typically carbon-rich material, aids in aeration, moisture management, and preventing compaction. It also moderates the heat from the decomposition of nitrogen-rich food. While many materials are suitable for worm bedding, I prefer shredded cardboard, like Amazon boxes. Shredded into strips and added to the bin, this bedding not only serves its purpose but eventually becomes worm food too. Yes, our worms even munch through our Amazon delivery boxes!
Our operation is large; but it’s not the largest, certainly not at a commercial level of operation. However we currently have 12 bins of various worms - about half Eisenia foetida and half African nightcrawlers. Most of the tubs are simple 4" high restaurant bus tubs that can be purchased in bulk from restaurant supply facilities.
And that’s our process.
Frequently answered questions
Where do you keep the worms?
They live in plastic tubs in our unfinished basement.
You’re working with decaying food matter. Doesn’t it smell bad?
There really isn’t any odor. The bokashi doesn’t smell great; but most of the time it is sealed in air-tight containers. It’s open to air, of course, when I feed the worms which is about once every 10-14 days.
Isn’t it a lot of work?
The worms can go many days with no attention at all. They work 24/7 in the dark. Periodically I feed them and about every 3 months, the worm castings need to be harvested; and that takes a bit of time.
It sounds gross.
That’s not a question; but have you actually considered how food gets to your table? Do you wonder why food warnings about E. coli are so common? And if you consume meat, have you considered how that slab of flesh ends up on your plate? It’s not pretty. And it’s shameful.
Is it expensive?
In our area, worms go for about $50-60/lb. I’ve probably purchased about 3-4 lbs of worms. The rest come from reproduction which under optimal conditions is quite rapid. The African nightcrawlers are champions of reproduction. Remember, worms are hemaphrodites, so there’s a lot of reproduction that can happen in those bins!