2015-16: i kept worms/ vermiculture for two years, until it became more practical to use outdoor compost piles.
How to Build Your Very Own Vermiculture System (Worm Bin)
adapted from a handout from UGA’s cooperative extension
- 10 gallon Rubbermaid, metal can, untreated wooden box … really the possibilities are endless. You just need something you can drill/ poke ventilation holes in
- Drill with a small bit (>1/2″)
- Old newspaper or corrugated cardboard
- A handful of garden soil or compost
1. Procure your worms. You want redworms, or European nightcrawlers (Eisenia fetida). Do not go for the big grey nightcrawlers they sell at bait shops — these are different. Redworms are the hungry guys that break down food the fastest and most efficiently. You can try harvesting them from your yard or compost pile, but it will be difficult to find them in large quanities. I ordered mine from a supplier recommended by my cooperative extension. They shipped priority from one state over, and thus arrived very quickly. I ordered one pound, and that set me back $30 with free shipping. They came bagged inside a box …
2. Prepare your bin. We bought our bin at Habitat for Humanity Restore for $1. I gave it a good clean, then drilled ventilation holes using a 1/4″ bit. You want to drill your holes around the top of the bin, making it harder for the worms to escape out of them. I spaced them an inch or two apart. Also drill 30-40 holes in the lid.
3. Prepare the bedding. Shred your newsprint into strips no larger than an inch. You can use both black and colored print, as the colored print no longer contains hazardous heavy metals. Once it’s shredded, throw it in the sink and water it. Wring the water out of the paper just like you would wring out a wash cloth. The worms obviously need moisture, but too much could offend them.
4. Fill your bin. Pull apart the damp newspaper, fluffing it up as you layer it in the bottom of the bin. You want a few inches of newspaper to start with (you can always add more later). Throw some garden soil (not potting soil!! Ew, chemicals!!) on top. The worms need the grit in the dirt to aid in digestion. You can also crush up some egg shells and throw those on top for extra grit.
5. Add your worms! The best step of all! The worms come packed in peat moss. I just opened my sack and dumped them all out. Leave the lid off. Within an hour they had all burrowed into the bedding, as they do not like light. Once they have all made themselves comfortable, you can put the lid on the bin. The next morning, I caught a few clumps trying to jail break … this is common as they are adjusting to their new home after shipment. Since feeding them, I haven’t had any issues.
6. Feed your worms. I waited about 12 hours to feed mine, just to let them adjust. I ground up a decent amount of table scraps in my food processor, then buried handfuls throughout the bedding. Burying the food is essential to prevent flies and odors. You can skip the food processor – it just helps to hasten the decomposition process. I will probably only do it for the first month or so until we are established. The worms eat slow at first. Here’s a list of what to feed them. Just like all of nature’s other cool kids (manatees and elephants), worms are vegetarians.
Worms will eat half their body weight per day. So if you started with a pound of worms (like I did) you can feed them a decent amount of scraps everyday. They will also double in population every 90 days, and self regulate their population once it reaches capacity. SO freaking cool! I am enamored with my new pets, and stoked to be pulling all of our food scraps out of the waste stream.
The worms chugged along in their plastic rubbermaid bin, churning out vermicompost that I used in my garden and on my houseplants. Eventually though, they outgrew their home …
I read Worms Eat My Garbage by Mary Appelhof, which I highly recommend. It’s simply written, has cool drawings, and makes vermiculture accessible, yo! In it, I learned that the castings (poop) the worms produce is actually toxic to them, and as a bin converts from vermicompost (partially broken down organic material) to castings, the worm population dwindles. Again, doh! I wouldn’t want to live in a sea of my own poop either. One method is to let the worms die off and the bin sit – this way, you will end up with straight castings instead of a mixture. The castings are nutrient rich, but also contain high levels of minerals and salts. They are using sparingly. The vermicompost mixture can be used similar to regular compost.
The downside to letting a bin completely convert is that you have to buy new worms to start a new bin. I got mine for $30 bucks/ pound, which ain’t cheap. I don’t want to have to keep buying worms; it fact, maybe I want to be a worm farmer … Anyways, I have decided to move to a different, larger system called a “flow-through,” which allows you to harvest castings while maintaining a worm population.
My mom, sister, and I built a fancy worm hotel while I was home for the holidays (I’m going to do a separate post on that beauty once I finish it). I’ve enjoyed raising worms, but the ole Rubbermaid system wasn’t cutting it. I found it inconvenient to have to go outside to dump scraps, it wasn’t big enough, and it circulated air poorly making it difficult to control moisture and temperature. If you are thinking about vermicomposting, the Rubbermaid is a great start. Hell, you can vermicompost in almost anything. But you can set up a Rubbermaid bin for $20-40 depending on where you get your wormies.
Worm Heaven is finally finished, and the new family has moved in. Many thanks to my mother and sister who helped (aka did most of the work) while I took pictures and bossed around. I’m not giving procedurals on this vermiculture system, as we have no idea whether or not it will work. Will the worms be able to “climb” the gaps between the drawers? Will it stay moist enough? Are the drawers big enough to accommodate our food waste?
Poor wormies. They were quite neglected during the move. Before we started packing, I made sure they were loaded up on food … then I don’t think I looked at them for one month. Luckily, they didn’t mind! When I pulled the drawer out the other day, I was met with my first batch of worm castings. Worm castings are the worm poop, and they contain high levels of nutrients and minerals.
These castings were like nothing I harvested from my first, plastic bin system. This stuff was light, dark, and smelled incredible. Not a bit of food was recognizable in it. There was only one small problem – the castings didn’t exactly end up where I had planned.
When we built Worm Heaven, it was designed to have four drawers in which the worms would live and migrate like any other system. Once the bottom drawer was ready for harvest, I would pull it out, move all the drawers down one shelf, then place the empty drawer on top to start anew. I tarped the bottom of the shelf frame to make sure leachate (worm pee) didn’t run anywhere.
Boy am I glad I tarped it, because all the castings fell through the wire grid to the tarp! You can imagine my surprise when I pulled the drawer out and saw a big, beautiful layer of castings. I inadvertently created a flow-through system! I decided that I will tarp the bottom of one drawer, and it would always remain on the bottom shelf for catching castings and stray worms. The other three drawers will rotate as usual.
In all my previous vermicomposting, I had always used shredded paper as bedding. I got it by the bagful for free from work, so it seemed as good as anything. Well, the worms turned their noses at it. Even though I had read that the worms wouldn’t care about the bleached paper, I should have known better. I wouldn’t want to live in that crap either! Not to mention, I don’t want it in my garden. Above is what the original tray looked like when I pulled it out. You can see – the worms ate all the food scraps an left the bedding. Typically, about half of the worm’s diet should be bedding.
Some wormy thought to finish this update:
- The coir might hold the worms and castings in place better than the shredded paper did. In which case, I won’t need the tarped bottom harvest drawer.
- I think the worms will like the coir more than the shredded paper, but I’m not happy with it as a bedding choice. The worm system needs to be sustainable, as in have no outside inputs. I want a closed system. The coir is pricey, and while I am willing to spend $$ for good seed starting mix, it seems ridiculous to spend that kind of money on compost bedding. Which is why the shredded paper was ideal – it was free, and by using it for worms I was pulling it out of the waste stream (we can’t recycle shredded paper in our county’s single stream). In my first bin, I used black and white only, unbleached shredded newsprint. I hated it. Tearing it into strips was labor intensive, and it always just bunched up. We don’t get the newspaper, so I would have to stockpile them from other folks, which was annoying. I might try leaf litter in the fall.
- As far as a closed system – this year, I used Root Simple’s recipe for seed starting mix and loved it. It calls for perlite, coir, and worm castings. So the idea is that I would be growing my own castings for use in starting mix, and as a back up amendment to cured compost from the outdoor pile. The starting mix in turn grows the plants that produce the foods that make scraps that feed the worms. Hooray, permaculture! (I know, the perlite and coir are outside inputs. The goal is eventually to have high quality enough garden soil that the starting mix could simply be soil mixed with castings. One can dream!)
- With the castings falling through, I have to separate the worms out and throw them back in the bin. This is time-consuming.
the last of the worms:
Worm bin is outside for the summer and those little guys are happily pooping away and multiplying and cohabiting with black solider flies and maggots and beneficial nematodes and just generally doing the amazing work that nature designed for them called ‘decomposition.’ Behind and under my potting table-bench are a selection of our edible and medicinal mushroom logs. We’re starting to see some white on the ends which means our mycelium is colonizing away and breaking down lignin and preparing to fruit to make more fungi that also does the amazing work that nature designed for it called ‘decomposition.’ And I have no idea what the amazing work nature designed for me is called, but I get a hell of a lot closer to it every day I spend with my hands in the dirt and the sun on my face.
The whole thing was an experiment that went … ok. I was never able to get the worms to “climb” between the sections, mainly because there just wasn’t enough food waste. Once it got hot in our home, the bin was attracting flies etc so it got moved outside. It faired well outside, but the once we moved to Oglethorpe we had a real compost area so the vermiculture system because obsolete and petered out.