I wrote this years ago, but finally posted it because members of a list I am on have been asking about vermiculture.
Even if living in the city without a yard, you can be Gaia’s steward. A worm farm produces fertilizer that’s even better than what’s created in a regular compost bin. (This is an instance in which city folk can outstrip their country cousins.) If you have no garden, make a difference by supplying your gardening friends with earth-friendly worm compost. You can also love up your house plants with low cost, homemade fertilizer that didn’t need to be shipped via gas-guzzling, air-polluting trucks.
Worm composting, known as vermiculture, is easy. I live on seven-tenths of an acre, but I keep a worm bin because it adds another way to be connected to nature, is fun, provides inexpensive, high-quality organic fertilizer, and utilizes my kitchen scraps year round.
The easiest container is a plastic storage bin with a lid. It shouldn’t be translucent; worms need darkness. You’ll want a container—mine is about 16″ L x 12″ W x 9″ D—in which you can put two to four inches of bedding. More bedding than that compresses, which isn’t good; wormies need air.
Punch air-holes—high up so that liquids don’t ooze out the bottom.
Shredded newspaper usually works as bedding. Most black ink used for newsprint nowadays is soy-based. You can call your newspaper to be sure. Non-soy-based inks are toxic to the wormies, the plants you’ll be fertilizing, the earth the plants are in, and anyone who eats the resulting produce. Colored inks used to be a no-no but I don’t know their current status, so I avoid them. Don’t use the shiny paper typical in magazines. I run newspaper through a paper shredder, but you can rip by hand.
Once bedding is in place, spray it with water until it’s quite
moist. Think of how liquid worms appear—they need things wet. Note that I wrote wet and moist, not mini-puddles. Sodden paper compresses into an airless environment.
To maintain a moist environment, re-spray as needed. When I kept my farm in the basement during the winter, I had to spray only once a week. However, upstairs mid-summer, I sprayed every few days.
Worms have no teeth. Provide something they can use to chew their food. The easiest thing is a handful of dirt. Fine sand or ground up egg shells also work.
Now the bin’s ready! Don’t get just any worms. Acquire red worms from a local bait shop or on-line store. Or contact your county extension and inquire whether they have Master Gardeners. Perhaps one of them has worms they’ll give away or sell. (In fact, Master Gardeners in my town helped me learn how to create and maintain a worm farm.)
Place the worms gently under the bedding. Worms don’t do well if
handled, so keep that to a minimum. Leave the lid slightly askew to allow more air in. Wash your hands well after feeding the critters or otherwise handling the bin.
Worms manage a wide range of temperatures, but don’t let it get anywhere near freezing, or so hot that you yourself can’t tolerate it. I’ve kept my bin in a partially heated basement in the winter, in a hot upstairs room during the summer. Both were fine.
It’s time to feed them. Worms eat almost anything: veggies, fruits, bread, cooked rice, banana peels, and coffee grounds. Don’t feed them oils, meat, poultry, fish, or milk. A Master Gardener told me that worms hate onions, citrus, and raw vegetables. She added that they need soft foods, such as cooked vegetables. It seems to me that my worms used to devour raw veggies, but lately I’m wondering if my memory serves me wrong: I’m having some trouble with my worms (more about problems with your bin later) so I am reappraising past events. For now: See for yourself if there’s something your worms hate.
Once a week, put some food in a corner of your container, at the bottom, under all the bedding—a banana peel, an apple core, scraps left over from chopping vegetables, or whatever. I use the same corner every week, then switch corners after a while.
How much food depends on the amount of worms. There are folks who know how to mathematically factor that exactly. Not me! I prefer a more, pardon the pun, organic method. If the bin starts to smell from rotten food, I’m putting in too much. If food’s disappearing too quickly, I provide more.
Therefore, in the early weeks, I check the bin every few days to see how things are progressing. By the way, worms don’t eat the food until it rots. They love yummy rottenness!
The more kitchen scraps you want to use up, the larger the worm population you’ll need, and the larger a bin you’ll need to accommodate them.
Harvest time! After a few months, you should have plenty of dark material in the bin. That’s worm castings, less officially known as worm poop. It is ambrosia for organic gardeners, and good for house plants, lawns, veggie gardens, and floral beds.
Worms can’t live in just castings—they are too toxic. When the bedding is almost eaten, it’s time to harvest. Doing so is a process. And is where I suspect I had trouble. Mind you, at first I harvested lotsa castings, repeatedly. Then my worms kept dying out, and I don’t know why (and I’ve stopped worm farming for a while, so haven’t had a chance to figure it out yet. But I wonder if I was under-harvesting, so that worms were in a toxic environment.)
In any case, I’ll show the two ways I know to harvest. Maybe you can tell me if one or both of these is incorrect. First method: Gently clear one side of the bin (hence called side A) by shoving all its contents on top of what’s in the other side (hence called side B), remembering that wormies don’t do well when handled. Put new bedding on the cleared side, and add food to it at the usual rate, for the next couple of weeks. The critters will recognize the nice new home you’ve made for them and, over a few weeks’ time, migrate to it. After a couple of weeks, check side B. If it’s relatively worm free, it’s yours! Once you harvest it, add new bedding to side B.
Another method: Leave the bin’s contents as is, but add no food or moisture to side A. Moisten and put food in side B only. For the next few weeks, some worms will migrate to side B. After side A has dried out for a few weeks, scoop it out and let it sit somewhere a while; its remaining worms will go to the bottom. Clear off as much of the upper portion as is worm free. That is your fertilizer. Put the remaining worms back into side A, add nice new bedding over them, and give ‘em the usual yummy food (food that is yummy by worms’ standards). Now repeat the whole process with side B.
Using your fabulous worm castings: A Master Gardener told me that, with house plants, she covers the surface of a pot’s dirt with a half-inch layer of castings. Another Master Gardener concurred, adding that you could, instead, just grab a handful of castings and sprinkle it onto the top of the soil. It’s a slow release fertilizer; when you water the pot, the castings leak in bit by bit. In the garden, put a handful around a plant. When transplanting, put a handful of castings in the hole, mix it into the dirt, then put in the plant.
Both Master Gardeners said that you can’t use too much. However, I was misinformed about that for a while. I thought you shouldn’t use too much castings—that more was not better. I would put only a teaspoon on top of the soil of my potted plants. I also would add castings to water and pour it into the ground to make my garden happy. When the water was gone, I would dump the remaining castings onto the garden dirt. Now I follow the more generous usage delineated above, but it does seem— though I can’t give you scientific evidence—that my earlier approach sure seemed to help my plants anyway. I still intend to put castings in water to water my garden.
I’m no vermiculture expert. My first batch of worms died after a year. Ditto my second batch. So I’m still learning. But, both those years, the bin produced mega-amounts of Gaia’ lovin’ fun and fertilizer.
Trying to figure out why my worms had died, I had a long talk with a Master Gardener who has successfully worm farmed for years. I explained that I couldn’t seem to get the farm cleaned, because the worm castings piled up too fast for me to stay ahead of them. At that point I had an “aha:” I remembered the huge number of teeny tiny worms my farm produced (red worms look like wee snippets of white thread when they are babies). I asked the Master Grander if perhaps my worm population had gotten too big for its container, creating more castings than I could keep up on, and hence an environment too toxic for worms to live in. She said, “I wouldn’t know. I never get too many because I’m always giving some away.” That seems a possible yes to my question. Next time I worm farm, if there is a population explosion, I’ll give some worms away.
Tending Mother Earth is a learning process. It is also humbling: There are always mistakes and more to learn. It is also satisfying. If you end up with a seriously smelly bin, dead worms, or other problems, call your local Master Gardeners for advice (if there is such a group in your area). Another option is Gaia’s Stewards, an online gardening group at http://groups.yahoo.com/group/gaiasstewards. Join the group and ask if anyone can address your problem. Together we can be Gaia’s Stewards. And the worms will join in.
Outlaw Bunny AKA Francesca De Grandis runs a Yahoo list called Gaia’s Stewards, at http://groups.yahoo.com/group/gaiasstewards, where both newbie gardeners and experienced green-thumbs share their journeys as caretakers of the earth.
