Here in the great white north, gardeners are dreaming of warmer days, when they can dig into damp spring earth. They’re sketching diagrams of their garden beds, deciding which summer vegetable will benefit most from last summer’s nitrogen-rich green bean plants, or which flowers will best complement the strawberry patch. In month or two, these planters will start seeds indoors, preparing for the time when night temperatures stay above freezing.
This time of year, outdoor compost piles, a rich source of nutrients for all those seasonal garden plots, are buried under piles of snow. But some locals are using this time of year to make their own rich compost indoors. Vermicomposting, or using worms for composting, is gaining popularity here in the Twin Cities.
Commercial worm composting kits are available at garden stores or online, costing anywhere from $90 to $200. But a do-it-yourself version can be made for under $50. Classes at local co-ops, costing about $40 for members and $45 for nonmembers, can supply you with all the materials and information you need to compost your food scraps indoors, in your kitchen or basement.
Jonathan Beutler, who teaches these classes, says the most important myth he’d like to bust about indoor composting is that it smells. If you do it right, paying attention to how much your worms are eating and making sure to bury new food scraps, Jonathan says, a worm compost bin “smells like delicious, freshly turned waste.”
The class I attended at The Wedge last week taught me more about worm livelihood than I ever expected to know. Jonathan has been composting and informally teaching his friends about vermiculture for about five years, and he knows his stuff. His hour-long presentation included worm diagrams and an overview of worm respiratory, digestive, circulatory and reproductive cycles.
The cost of the class included materials, and we finished the evening with an assembly line, in which all 18 students put together our own fully functional plastic bins, 26 inches long, 16 inches wide, and 17 inches tall.
Jonathan had already drilled holes into the bin floors and lids, and we each received a second bin for drainage. We filled our new bins with worms, sand, and dampened coconut coir, a fibrous material made from coconut husks. All I needed to add when I got home was a handful of food scraps, which should be replenished at least twice a week.
As my worms get comfortable in their space, they’ll digest my food scraps and their damp coconut coir into a concentrated compost, rich in nitrogen, potassium and phosphorus. They’ll also produce a liquid “compost tea,” containing the same nutrients. I can feed these materials to my houseplants, or save this compost and tea until the snow melts, when I’ll mix it into the soil in my community garden plot before planting spring and summer veggies and flowers.
As they process their food, my 30 or so hermaphroditic worms will also begin to mate. Jonathan says they’ll fill the bin with bouncing baby worms, reaching capacity in six to 12 weeks. But they won’t overflow the bin, because they will stop reproducing when they fill their limited space. If any of my friends ask me to contribute worms to their new starter vermicompost bins, my remaining red wigglers will begin reproducing again.
Every couple of months, I’ll need to push the compost, worms and all, to one side of their plastic bin. Then I’ll add a pile of shredded newspaper or a brick of coconut coir (about $2.50) to the empty side, with a spritz of water and a handful or two of new food scraps. Over the next few days, the worms will move from the processed compost to this fresh material, and then I can collect the finished compost.
Vermicomposting uses red wiggler worms, a breed found in nitrogen-rich mediums such as manure piles. Outdoors, they live near the surface of the soil, not more than 18 inches deep. Night crawlers, a type of worm perhaps more familiar to those who fish, don’t work well for composting, because they live much deeper in the soil, and dislike being kept in bins.
The first formal co-op class Jonathan taught, two weeks ago at Seward Co-op, sold out quickly. My class at the Wedge was nearly full. He says he’s been discussing more classes for the spring, but nothing is scheduled yet.
So if you’re dreaming of some red wiggly friends to feed, keep an eye on class listings at your local co-op. In the meantime, you might look into the book Worms Eat My Garbage, by Mary Appelhof, which Jonathan describes as the bible of vermiculture. And in time, perhaps the residents of our currently frozen cities will help Jonathan reach his goal of putting a worm farm in every home.