Wednesday, June 10, 2009
The Clean Dirt
What is worm composting?
Worm composting is using worms to turn kitchen scraps into a rich, natural fertilizer. There’s something that looks, smells, and feels like dirt—that’s the worm compost or “castings,” and there’s “worm tea” which is the moisture and liquid produced by the worms and also from the water that you pour over the worms to keep the whole thing moist (they like moisture)! If you have purchased a worm kit, your kit probably has a tray that will collect the worm tea.
How did you get started w/worm composting and how long have you been doing it?
I was living in Berkeley as a college student in the early 1990s when I first heard about composting and worm composting. I was really intrigued by recycling, composting, and reducing waste. I don’t know why that kind of stuff excited me so much. I was attracted to the idea of reducing what I throw away everyday. My landlady had a vegetable garden and she composted. I literally saw her yard waste turn into soil when she turned her compost pile. I then came across an article about worm composting; it talked about a guy who was selling handmade, wooden worm composting boxes. I called the guy who made the boxes and hopped on BART to get to him (I didn’t have a car and didn’t know how to drive anyways). I paid $45 for one of his worm boxes that was about 4”x 3” x 3”. I really don’t know how I carried that thing from the BART station to my rented room in a house, but I somehow managed!
I bought my own worms at a local bait shop, made a bed for them using damp, shredded newspapers, threw in a little dirt from the garden and started composting. I did this for less than a year before I left Berkeley for law school in Los Angeles. I was able to gather several harvests of worm castings which I put in the vegetable garden. I remember that the worm castings smelled rich and sweet, like clean dirt. It was really cool.
I didn’t know how weird “worm composting” was until I left Berkeley to go to UCLA for law school in 1993. When I told my law classmates that “I used to have worms for composting,” of course they thought I was crazy. Nobody had ever heard of it, and apparently nobody cared about reducing waste in Los Angeles. I stopped recycling and worm composting when I came to Los Angeles. When I went back to visit my landlady up in Berkeley, I asked her how the worms were and she said she had tossed them into the garden soon after I left and assured me they were happy there. I now know the red wrigglers you get for worm composting don’t survive in a garden, but that’s okay. She at least threw them into back into nature.
I restarted worm composting in mid-March 2009. It had been nearly 20 years since I last worm composted, and I had been feeling a twinge of guilt throwing away all the tea bags, broccoli stems, apple cores, and banana peels throughout the years. What got me started again was listening to Good Food on KCRW (one of the station in L.A. that carries NPR). The hostess, Evan Kleinman, was interviewing a Canadian woman who was selling worm kits over the internet for about $160 and I thought “I used to do that, and I’ve wanted to do it again for such a long time, so what’s stopping me?” I did a quick internet search and found out that my very own L.A. County was offering Smart Gardening Workshops at various locations and selling subsidized worm & composting starter kits. I went to the very next workshop and purchased my well-made, well-designed worm kit for only $65. There were quite a few people at the workshop who all wanted either a composting bin or a worm kit. It was heartening to witness. So, for this second go-around, I’ve only been worm composting since March of 2009, about 2.5 months. I like my second bin a lot more. It’s made out of 100% recycled materials, is designed to keep out flies, has a tray to collect worm tea, and came with instructions, bedding material, and a half pound of worms!
Tell me about your worms—are they a certain variety, or do regular old earthworms work for this job?
Earthworms absolutely do NOT work for worm composting. Earthworms like to go deep and come back to the surface. A worm composting box is not very deep, so the earthworm would not be happy living in the box. The type of worms you need is red wrigglers, or tiger worms, (Eisenia fetida) and they are surface dwellers. (Click here to see a photo of Pei Pei's worms in action.)
Worms can eat about half their weight every day, so a pound of worms can eat a half-pound of food per day. That’s a lot of apple cores!
My worms had to get used to their new environment, and in the beginning, it seemed they were trying to “escape.” Every time I lifted the lid to the bin, I’d find worms on the side, on the lid—they didn’t seem to be eating! I’d use a pair of chopsticks to push or flick them back into the soil. But after about 10 days, they settled in and were munching on the banana peels I had thrown in there. I tended to fret over them—always checking in on them, needlessly opening up the lid, causing them to wriggle down into the soil/bedding (they don’t like the light), checking on the food level, and looking for uneaten food that has gotten moldy. I’m much better now.
The worm population will adjust itself. If you don’t have lots of food to offer them, some members will eventually die. If the food level picks up, then they will breed and eat more. I have found the tiniest, littlest baby worms imaginable—they’re translucent! It’s very cool!
They like a moist environment, so you have to occasionally pour some water (about a cup or so) over everything. But once I made it too wet and for the next few days, I again found worms on the sides and on the lid of the bin. If that happens, just throw in some dry newspaper or cardboard to absorb the excess moisture.
What do they eat?
I cook a lot of vegetables, and almost all the trimmings can go to the worms. They love to eat apple cores, banana peels, coffee grinds, coffee filters, tea bags, vegetable and fruit trimmings, and things like that. They can eat shredded newspapers, napkins, and paper towels forever. What you can’t throw in there is protein and dairy products, so no meat, fish, raw eggs, nor cheese. No oils or grease, either, and avoid acidic fruits (like citrus). A few carefully rinsed out egg shells (crushed) is good to add, to help maintain pH levels.
What I like to do is chop their food into small pieces. This is where my Knife Essential Skills, courtesy of a cooking lesson at Sur La Table, has paid off! If you chop the food into small pieces, they can eat it more efficiently. I also cover what I throw in there with a few layers of damp newspaper; doing so really helps prevent the bin from drying out, and also helps prevent the food from attracting flies or bugs.
You have to remember that the food doesn’t just disappear overnight. It disappears slowly over several days, each day it’s a little mushier, a little bit more decomposed (but not smelly), and it’s not until weeks go by that you recall, “Hey, I threw in 3 banana peels about 1.5 weeks ago, and it’s gone!” Meanwhile, you keep adding new food every day, but not too much. You have to adjust occasionally. I have thrown out food that has gotten moldy (the worms won’t eat moldy food); it was when I got lazy and didn’t chop up the banana peels into bits.
You mentioned that you don’t have a garden. What do you with the compost when it’s ready? (and how do you know when it’s ready?)
I am less interested about the worm compost than I am about reducing what I throw out. However, I have used diluted “worm tea” to water my various houseplants and orchids. You have to dilute it because otherwise it is too strong. It could just be in my head, but I swear, after I watered my orchids with diluted worm tea, it seemed as if the shoots and buds grew overnight, and actually, come to think of it, I have no problems with mealy bugs this season.
I think I would just use the worm compost on the landscape of my condo complex. We have a communal loquat tree that I would like to fertilize, too. Or I could secretly fertilize the various plants of my coworkers and see if it makes any difference on the anemic office plants.
The worm compost will be ready in about 4-6 weeks. I’m sure I am able to harvest some compost right now, but as it’s not my main objective, I’m not that eager to harvest.
What is it about worm composting that gets you excited?
What really gets me excited is that worm composting is my small way of reducing the food stuff that I throw away. Think about all the coffee grinds each office throws away every morning; wouldn’t it be cool if you didn’t have to throw any of that stuff away, but recycled it instead? Wouldn’t it be awesome if in the process of recycling your coffee grinds and filters, you actually produced nutrient rich fertilizer? Knowing that you could, why wouldn’t you do it? It’s really cool when you make something like banana bread (that’s one of the very few things that I bake) and you throw NOTHING away in the process. All banana peels and egg shells can go into the worm bin. I just find that very satisfying.
Do you have questions or comments for Pei Pei? Email them to me at joanna (at) greatturtle (dot) com and I will pass them along.