Composting is great. For the small effort of dumping your fruit and vegetable scraps, coffee grounds and occasional leaf litter in a backyard bin or pile, you can produce a rich soil additive to use in gardens, windowboxes, planters and pots.
But what if you’re lazy?
You like the idea of turning your kitchen trash into fertilizer, but walking out to the back corner of the yard to deposit your compostables sounds like too much work. Now you, too, can start composting–from the comfort of your home or apartment– with a worm bin.
Vermicomposting, or composting with worms, produces great humus just like traditional composting. But worms do their work in a container you keep in your house or garage and they work much faster than the microbes at work in a backyard compost pile. For people in northern climates, like me, the worm’s comparative speed boost is even more dramatic because cold winter temperatures slow or stop the microbial decomposition in outdoor compost bins. Done right, a worm composter doesn’t smell strongly or badly and shouldn’t support fruit flies.
I’ve wanted to give vermicomposting a try for a while and decided this fall was the time to make it happen. All it takes are the right worms and a suitable bin for them to live in. Besides, now that our monarch caterpillars are all gone, the house was feeling a little empty without some invertebrates to feed.
The Right Worms
When it comes to vermicomposting, not all worms are created equal. Certainly digging earthworms out of the garden isn’t likely to yield a successful worm bin. The preferred compost worms are Red Wigglers because they eat voraciously, breed prolifically, live densely and don’t burrow deeply. You can find Red Wiggler worms at garden stores, bait shops, and online.
Or you can do what I did and get some worms from a neighbor with a worm bin. Because the Red Wigglers reproduce quickly, it won’t be long before my friend’s donor bin and my new composter are both fully populated.
Building a Worm Composter
Most places that sell worms also sell commercial worm compost bins. But worms aren’t picky about their digs and for a fraction of the cost of a retail composter you can make a worm bin from ordinary plastic storage bins and a bit of hardware. A google search for “worm bin plans” will yield dozens of websites and videos.
With so many options, I looked at several ideas then picked the plans that looked best to me. My bin design comes from the Oregon Soil Corporation, which has nice printer-ready build instructions with illustrations and a materials list.
The worm bin plans call for three 10-gallon Rubbermaid Roughtote bins, which I found at True Value Hardware, as well as some 1″ x 2″ lumber, screws and insect screen that I happened to have on hand. It took me about two leisurely hours to complete the project, and most of that time was spent drilling holes in the bins.
I lost track of the number, but I drilled a lot of holes. The two composter bins have 1/4″ holes throughout the bottom of the bins and in a single row around the bottom of the bin’s sides. These holes allow excess liquid “leachate” to drain from the composter and also facilitate movement of worms from the lower composter to the upper composter when the lower bin is full of processed humus. The third bin is the base and retains a solid bottom to catch the leachate, but has holes on the upper sides to provide ventilation to the system.
Hole Drilling Tip:
To get clean holes in the plastic bins, drill them from both sides. Push the “blowout” on the backside of the first drilling back into the hole before drilling through the hole again from the other direction. Any remaining plastic burrs can be torn away with your fingers.
The construction of the cover for the bin was one of the details that attracted me to this design. Rather than perforating the lid or the top perimeter of the bin for ventilation (worms need to breathe, too) this design uses a big mesh-screened cutout in one of the lids, topped with a solid second lid. With spacer blocks between the two lids this cover design provides great ventilation for air and moisture while retaining the dark environment worms prefer. To make the cutout, I drilled holes at the corners of the cutout area then cut between them with my razor knife. (Yes, I’m a lefty.)
To make the top as stable as possible and to make it easier to line up the lumber when I put the lid assembly together, I took the added step of joining the screen frame members together with my Kreg jig. Then I stapled the insect screen to one of the wooden frames, cut off the excess screen, and finished the lid assembly with 1 1/4″ screws set in pilot holes.
Worms at Work
With my worm composter built, I prepped my bin to be a new home to some hungry Red Wigglers. I started out with a nice bed of shredded newspaper and then added the worms given to me by my neighbor along with some compostable scraps from my kitchen. Then I covered all of that with another layer of shredded newspaper. Future additions to the bin will repeat the food-newspaper layering so that there is always newspaper covering the food scraps.
A week or so after I started the vermicomposter, I took some pictures of the worms’ activity. When I opened the lid, there was some condensation on the inside of the lid indicating that the bin had a good moisture level for my wormy buddies. Looking into the compost bin itself, the newspaper was moist and there were visible worm castings on the surface.
For now I have kept the worm bin in our mud room, on the main floor just around the corner from the kitchen. There is no discernable odor from the bin and if this continues and the room temperature stays cool enough I may keep the bin there because it’s such a convenient location.
When I took the worm photos above, my 4-year-old was by my side and he said, “Aw, they’re cute little worms!” Other than this brief gawking, however, the kids have left the worms alone. Before this, the only checking we had done was to lift the lid a couple times to listen to the worms wiggling through the compost. That sound is undeniably gross but it’s also irresistibly cool, especially to my young boys. The worms have made composting interesting to my kids and they keep asking me, “Is it time to feed the worms yet?” That’s something that never happened with our backyard composter.
This project cost about $30 for the materials, but readers without materials on hand or access to free worms might have to pay up to $50 for the project. This is still a far cry from the $100+ cost of commercial worm bins that don’t pack all the awesome DIY fun. If you’d like to follow the same plans I did, you can get the instructions here.
If you are a worm rancher like me, share your experience or tips in the comments below. As always, your questions about this project are welcome, too.
Disclosure: I was one of the bloggers selected by True Value to work on the DIY Squad. I have been compensated for my time commitment to the program and my DIY project as well as my posts about my experience. I have also been compensated for the materials needed for my DIY project. However, my opinions are entirely my own and I have not been paid to publish positive comments.