The Third Tray is On!

The third, and final, tray was added to our Can-O-Worms on July 27, 2008. This layer requires no worm bedding, as the worms reside in the lower layers, and show up in the topmost tray only at mealtimes. In approximately 3 months or so, we should have our first vermicast harvest. Stay tuned.

The Adventures of Herman, the Squirmin' Worm

"The Adventures of Herman: The Autobiography of Squirmin' Herman the Worm", a kid-friendly, educational, and cute website, comes courtesy of the University of Illinois at Urbana-Champaign Extension Urban Programs Research Network. The site offers a brief history of vermicomposting in America, offers instructions on creating and maintaining a worm bin, and reviews essential information on worm anatomy, feeding, and reproduction, as well as an overview of worm bin environs.

Some wild facts about worms: First: they're hermaphroditic! Mature worms have both male and female reproductive parts located in their clitellum, a light-colored, swollen, ring. When worms mate, they join, with their heads pointing in opposite directions. They exchange sperm, which is stored in sacs, and cocoons form on the clitellum of each worm. As the worms back out of the cocoons, they deposit sperm and eggs into the cocoons. Once the cocoons close, fertilization takes place. Cocoons can be produced on the order of once a week. Each cocoon holds 1-5 worms and can lie dormant until ideal (read: moist) conditions emerge: they take 2-3 weeks to hatch.

Worms have five hearts, and since they have no lungs, oxygen diffuses across their moist skin, moving from the area of higher concentration (the air) to the area of lower concentration (inside the worm). This is why it's essential not to feed the worms oily food, as it interferes in absorption.

Worms have small mouths, located in the first anterior segment, hence can only feed on small things: bacteria, fungi, protozoa, and organic material. A flap, located near the mouth, called the prostomium helps keep unwanted particles out. Since they have no teeth to break down their food, an organ called a gizzard does the work. Some worm sites suggest adding garden lime, eggshells, or sand to aid the worm in grinding down the food. When the gizzard contracts, the small grains and grit inside of it compress against the food, grinding it into digestible particles that subsequently enter the intestine. There, digestive enzymes break down the nutrients, which pass through the intestinal wall and are absorbed in the bloodstream. Undigested waste material passes through the anus as vermicast.

To some extent, worms can regenerate: if their posterior (tail) end is severed, they can grow a new tail, but the same cannot be said if their anterior (head) is lopped off.

Tea, m'dear?

When you examine vermicomposting sites on the Internet,there seems to be a great deal of confusion regarding what one calls the dark brown liquid that's produced as a by-product of the worm bin, and which must periodically be drained from the side spigot.

This liquid is properly called leachate, which the Oxford English Dictionary On-line defines as "(A quantity of) liquid that has percolated through a solid and leached (extracted) out some of the constituents." The University of Hawaii's College of Tropical Agriculture and Human Resources (UH-CTAHR), in their August 2005 publication HG-45, "Small-Scale Vermicomposting" (Selden, DuPonte, et al) notes that leachate may "have a slight odor" and "can be used full-strength or mixed with water. Use it to water plants or dispose of it on your compost pile." S. Zorba Frankel, in "Compost Tea or Leachate" from Worm Digest #22, however, warns that watering with leachate might not, be good for plants: "When a liquid seeps through a material containing decomposing organic matter, some of that organic matter is carried along in the water. When it leaves the system, carrying with it undecomposed organic matter, we call it leachate. Now, water does not allow enough oxygen to diffuse into it to support aerobic microorganisms, and so anaerobic micororganisms are encouraged. These anaerobes produce some undesirable byproducts that are not good for plants."

In contrast to leachate, "worm compost `tea' is made from finished compost and involves a separate process" (UH-CTAHR's HG-45). Vermicast tea, sometimes known as worm tea, is a suspension made by soaking finished castings in water. The resulting "tea" can be used either as liquid fertilizer to water plants, or as a topical foliar application.

Here's a simple vermicast tea recipe, from tcdutch at the GardenWeb vermicompost forum: "take two tablespoons vermicompost and add it to one quart of water. Let it steep for a day, mixing occasionally. Then add it to your plants or spray it on their leaves."

You can find a more complicated recipe for aerated compost tea at the Pennsylvania Department of Environmental Protection. They state that compost tea is a sustainable and safer alternative to chemical-based fertilizers, pesticides, and fungicides and offers the following benefits:

* Increases plant growth
* Provides nutrients to plants and soil
* Provides beneficial organisms
* Helps to supress diseases
* Replaces toxic garden chemicals

For added nutritive benefit, one can also add seaweed emulsion or fish emulsion, presumably for the extra nitrogen. Why aerate, you ask, when the 2T vermicast + 1 qt. H20 is so simple? Here's why: oxygenating the tea helps create aerobic conditions that reduce phytotoxins and phytopathogens, a.k.a. things which can damage and/or kill your plants.

While browsing articles on compost tea, I came across an NPR audio file and article on compost soup, from Ketzel Levine's series, Talking Plants.

To find out more about the science behind compost tea and how it does all of the above, check out this fascinating article by microbial ecologist, Elaine Ingham. Ingham underscores that compost tea enhances beneficial microorganisms in the soil foodweb, organisms that die when we pollute the air or use conventional fertilizers and pesticides to kill off harmful bacteria, protozoa, nematodes, and fungi.

As The Worm Turns

Today, I added the new working tray to the top of our classroom worm bin, giving the critters a new penthouse abode. This new working tray, unlike the first, does not require worm bedding material, as the worms supposedly zip down to the first, bottom tray when not feeding, so as to avoid light.

As the castings in the first tray were abundant, too much for the new working tray to fit snugly, I scooped out the excess castings, added the remains of the old damp cover--now shreds of moist newspaper, peppered with worm eggs--moved the lot into the bottom of the new tray, and added some new food. I'm sure that the worms are lean and hungry, since I'd deliberately stopped feeding them for the last two weeks to ensure that any remaining organic material had biodegraded prior to the addition of the new tray.

A fun fact about the worms: they work as a nifty natural barometer. In high humidity, especially right before a big rain, they migrate upwards. I've been gingerly opening the cover as of late, as I can usually expect to find clusters of worms clinging to the top. Apparently, the action's instinctual, as this move saves them from drowning if they were in the grand outdoors and subject to floods.

Well, We're Movin' On Up...

Close-up of a worm egg capsule.


The worms continue to progress well. 2.5 months after we first started the worm bin, they're nearly ready to move up to the next working tray: the vermicast, as noted in the instructional booklet which came with our bin, is now at an inch above the inner plastic ribs of the current working tray. In order to prepare for the big migration and the addition of the new tray, we've stopped feeding them, in order to ensure that there's little to no unprocessed organic food still remaining in the bin.

Apparently, the worms have been eating well: they've been congregating en masse, a wriggling red bolus within the damp layer newspaper covers and laying eggs, sometimes termed cocoons, like mad. The egg capsules are ovoid, tapered to a point on two ends, and resemble orzo, only in miniature, a little smaller than grains of rice. See above graphic for a close-up.

Foods that Worms Love, and Foods They Don't

Pikake: worm delicacy.


After observing the worms for the past month and a half, I've noted the following observations about their likes and dislikes:

Love: papaya shells, strawberries, melons of all varieties, mango, cucumber, squash, potato peels, grains: rice, cereals, bread, eggshells, coffee grounds, tea leaves, pears, tomatoes, basil, rose petals, gardenias, and pikake. I received a beautiful pikake and rose lei for my birthday, given to me by a former student, Q., and after a few days, dismantled the withered flowers from the string and placed them into the bin. The worms devoured them within the day. The worms also enjoy damp newspaper shreds, bedding in them, hanging out in clumps within the layers of the "damp cover", and eating holes in the paper. According to the Cornell University Agriculture Extension website, a certain percentage of newspaper shreds to organic waste is not only necessary for optimal decomposition conditions, but will also offset any odor problems caused by excess organic waste.

Neutral: banana peels, apples, lettuce, green, leafy vegetables. These do get eaten, but not immediately, like the above.

Slow to process: onions, shallots, grapes.

Do Papaya Seeds Make Worms Sterile?

Papaya seeds and worm sterility: another wormbin legend debunked!


When I met with C., the director of Hogwarts' Center for Public Service, a few weeks prior to our worm bin installation, she provided me with a copy of the instructions that the Center places on its worm bin, offering guidelines on what/what not to put into the bin. The following dire caveat caught my eye:

1. Do NOT add the following:
• Papaya seeds: makes us sterile!

While I would've never thought to have placed papaya seeds in the bin anyway, since they're hard objects that'd be slow to biodegrade, naturally, I wondered whether the warning was true or apocryphal. So I Googled "papaya seeds worm sterility" and discovered the probable source. Mindy Jaffe, the owner of Waikiki Worm and the most well-known of Hawaii's worm suppliers and vermicompost educators, warns against feeding worms papaya seeds as "they will render them temporarily sterile". Hmm. I decided to pursue my research and attempt to dredge up some reliable scientific sources that definitively linked papaya seeds to worm sterility. If this was true, I wanted to know what the underlying cause was…it sure seemed questionable. After all, papaya seeds are definitely edible—would consuming papaya seed dressing, for example, render humans sterile, temporary or otherwise?

After doing an Internet search, I discovered the following:

1. Apparently, in some cultures, e.g. Indian Ayurvedic medicine, papaya (not just the seeds, but the fruit itself) is traditionally used in indigenous and naturopathic medicine as a vermifuge: a means for expelling intestinal worms (no mention of earthworms here, nor of the supposed sterilizing effects). Also, papaya apparently has anti-nematodal properties as well.

2. The following rationales were provided as to why papaya could be an effective vermifuge:
-Papain, the active enzyme in papaya, eats away at the protective outer cuticle of worms. I can't speak for intestinal worms, but given the number of people who've successfully fed papaya shells to their composters, who've subsequently thrived, the theory sounds questionable. Apparently, the effect is lessened in the presence of digestive juices, which might account for why the worms don't seem to be suffering ill effects.
-Papaya seeds contain a chemical, benzyl isothiocyanate, that is an anthelminthic, that is, a medicine of use against intestinal worms. As the papaya matures, the level of this chemical decreases in the fruit's flesh, but increases in the seeds. Alas, like papain, it's also apparently unstable in the presence of digestive juices, so it couldn't be particularly effective as such.

Vermicast, here we come!

Glenn Martinez, getting cosy with a Perionyx excavatus!

This semester, Hogwarts Academy generously provided me with a Wodehouse Sustainability grant to research vermicomposting: the act of using worms to break down organic wastes into rich vermicast, a nutrient-rich medium suitable for fertilizing one's garden. In other words, worm poop! The title of this blog, "Earth Dragon", comes from a Chinese term for earthworm: apparently, the Chinese have long employed earthworms in agriculture and admired the powers of this humble organism to generate rich soil with minimal maintenance.

On February 20, 2008, Glenn Martinez, proprietor of Olomana Gardens, set up a Can-O-Worms vertical continuous flow worm composting system in my classroom: an unassuming, black, rigid plastic tray with feet and a side spigot. Glenn, formerly an electrical contractor, started Olomana Gardens, an organic permaculture farm, in Waimanalo 12 years ago. The premise of permaculture: the farmer mulches the soil, scatters wood chips over all, tractor-tills the ground, then runs worms through it. The heat in the pile rises to an internal temperature of 170 degrees after 3-4 days and can spontaneously combust, as a result of methane buildup inside the pile--just in case you were thinking that farming was some bucolic, sedate activity. As an adjunct to permaculture farming, Glenn got into the worm business as a side-line, and now sells both composters and tillers.

Luckily, we were blessed to not have to purchase the two pounds of worms recommended by Glenn for optimal worm bin functioning, as they are spendy: a whopping $40/pound! Instead, A., a Hogwarts Grade 2 teacher, and the campus worm guru, generously shared "worm run"--the starter material containing our initial colony of worms--with us--a 7 year old messenger, face intent with purpose, arrived at the door of our classroom, bearing a large white bucket of worms.

Although redworms, also known as red wrigglers, are apparently the favored composting worm of choice in the continental United States, in Hawaii, the Hawaii Department of Agriculture sanctions only one type of worm for import into the state: Perionyx excavatus, also known as the Indian or Malaysian Blue Worm, which is suitable for tropical climes and hardy. If left alone, the Indian Blues migrate to another pile. Glenn claims that they are "like alley cats: they'll do anything to survive", unlike the red wrigglers, who will die if not fed. My students in attendance flinched when Glenn noted that this species of worm can grow up to 24" in length, and have grown as long as 6 feet in Australia. (Hmm...the latter story sounds suspiciously apocryphal to my ears, but that being said...) Composting worms are epigeic worms, surface dwellers that consume decaying organic matter on the surface of the ground, in contrast to endogeic worms, the subterreanean tillers that one normally pictures, when one thinks of earthworms. Glenn sells his tillers too, which were already on the premises of his property when he purchased it, at a hefty $2 per worm. Although that sounded pretty exorbitant to me, apparently the investment is worth it, as one worm alone can till 2 feet worth of hard clay soil.

So what's the big deal about Perionyx excavatus? Plenty. On the farm, Glenn described how the interns muck poop and pile it in a large heap in the barnyard. When they add five pounds of worms to said pile, they will eat all the way down in 90 days. That's a lot of soil!

The word "vermicast" derives from two languages: "vermi-"= Latin for worm; "cast" from Old Norse, "kasta"= to cast or throw. Glenn passed around a sample of the finished vermicast, and invited us to sniff it: very innocuous stuff, dark and rich like coffee grounds. Those present were greatly surprised to find that it had little smell, perhaps the faintest trace of rainforest, but little more.

Glenn also showed us a steel device called a "soil blocker", which shapes soil seed pots. Unlike seedlings in normal plastic pots, where watering expands and contracts pot, stunting the plant, seedlings planted in vermicast pots experience no dampening-off or transplant shock. All you have to do to get optimal results, Glenn explained, is dig a hole, put vermicast in hole, then plant the seedling. I chuckled when I saw Glenn's seed blocker, recalling the tour I'd taken of Hogwart's Public Service Center a few weeks earlier. The Center boasts a worm bin, and someone had left a number of seedling cubes constructed of vermicast in a foil-lined cardboard soda flat, right on top of the main table. If not for the slight round indentation on the top of each cube, it looked all for the world like an inviting pan of homemade chocolate cake: a dangerous proposition, with so many hungry students about, trolling for food!

I suppose that consuming said seedling cubes, other than being a nasty surprise, might actually be good for humans. Glenn noted that soil, prior to adding worms, generally possesses 8-14 nutrients: nitrogen, potassium, phosphorus, and other trace minerals. However, adding vermicast and worms produces a 700-800% increase in traceable elements in the soil. Interestingly enough, the vermicast apparently is relatively pathogen-free, even if the worms are fed manure. Glenn cited a statistic where human sewage was processed by worms, and in five days, scientists found it free of disease-carrying pathogens. Why? we're not sure: perhaps worms are selective and only eat the bad pathogens? And in the 2000 year or so history of using worm technology, Glenn said, no one has reported an infection from contact with vermicast--skeptic that I am, I mentally added "None reported, that is." But, that being said, Glenn's farm workers also deal with vermicast on a regular basis, and no one has gotten ill either. Some additional benefits to vermicast: if the worms receive a mixed diet, the castings are odorless, pH neutral,and unbuffered: they can be administered directly to plants without the burning associated with commercial chemical fertilizers.

The benefits of having a Can-O-Worms system like the one currently in place in my classroom: it's all-black, as worms are light-sensitive and like hanging out in the dark, and made from recycled plastic (#2: in case it broke down and you wanted to recycle the pieces, it could go in the "Mixed Containers" section of the City and County recycle bin). Supposedly, it'll keep everything odor-free if used indoors: I sure hope so! Structurally, there's a cone in the center of the bottom layer, and ventilation for aeration. The attached spigot at the base allows you to drain off the liquid which is a natural by-product of the decomposition process. The actual worms go in the second layer, which lies on top of the base. Initially, you need to provide them with bedding material: sawdust, shredded newspaper, or in our case, a commercial product designed especially for the Can-O-Worms system. The commercial bedding made of coir, or coconut husk, is sustainable; the peat moss that used to be the standard worm bedding material can't be exported anymore. The coir is compressed in a worm bedding block, which is pH neutral, fibrous, and holds moisture. The worms not only like lounging in it, but will also nibble on it, as well. To the bedding, one adds a bucket of worms: at least 2 pounds is optimal for this system. Worms enter puberty at four months of age; hermaphroditic, they mate head to tail. A worm lays approximately 10 eggs a week, which will hatch after 3 weeks.

So doing the math, 1000 worms will produce 10000 eggs after 10 weeks, creating exponential population growth. Food, in the form of organic waste, preferably pulverized or broken into small fragments, may be added, a large handful a day, in a circle. No more than 2 cm of food should be added over half the surface of the working tray. Apparently the worms do eat everything organic--apparently Glenn fed his a dead horse--but in indoor systems, you avoid feeding meat, dairy, or oily foods, to keep down the stench. Moist shredded paper is also added, as well as a damp cover (e.g. moistened newspaper, burlap) to help keep light out. The worms eat weight a day; pre-blending helps the worms eat better, but is not necessary. The air holes on cover let material aerate.

As the worms process the garbage into vermicast, the tray will fill up with the castings. Subsequent trays--2 more Working Trays in addition to the initial one--are added once the castings are 1/2 " above the plastic ribs on the inside of the tray. When the third Working Tray is filled, the first Working Tray is ready to empty: the contents will look like coffee grounds. Once emptied, the First Working Tray goes to the top, becoming the new Third Working Tray, and the process resumes again.

The large-scale applications? Glenn cited a local golf course that used to spend $350 a week to remove waste from its grounds, and which also produced lots of run-off from chemical fertilizers. Apparently, they've cut their maintenance costs from $1000 an acre per year to $80 an acre per year by using vermicast: it costs $1 for a pound of vermicast.

And obviously, there's major implications for a school like Hogwarts, which produces lots of organic waste. Obviously, if we're not able to convert the waste, it poses a major landfill problem, not to mention the monetary costs: approximately $1200/bag to process. As we live on an island, it's abundantly clear that we need to do something to save ourselves from becoming awash in garbage. I hope the worm bin represents a do-able step towards a more sustainable future, for ourselves and our posterity.