Notes from Windward: #66


Magic Worms

sustainability's tiny alchemists

     We're taught early on that "you can't get something for nothing," and in the consumer world that's true enough, but sustainability operates on an entirely different calculus, a context within which everything has value. Our task as stewards is to facilitate the transformations that keep the circle of life revolving--it's a world in which each actor, however humble, has a role to play.

the "Warmerator"

     Perhaps the least appreciated part of the entire process is the worms and larva that transform "waste" into resource, the creatures that close the circle and keep the ecosystem viable. It's not much of a stretch to say that all life on earth is dependent on the fertility that worms and larva provide, and that any attempt to create sustainability that doesn't facilitate their work is doomed from the beginning.

     To discuss their role in more pragmatic terms, worms and larva transform materials such as leaves, manure and offal into two things: (1) more worms and larva, and (2) nutrient rich soil. The former can be combined with grass to create fish, duck/chicken and rabbit food, and the latter can be used to ensure the continued productivity of our vegetable gardens.

     It's important to remember that while an element may be present in the soil, it may not be in a form which is easily assimilated by plants; it's the soil's journey through the digestive system of the worms that breaks down chemically complex materials into elements that can be absorbed and used. It's a slow process whose result can be compared to the way that land will show a burst of fertility the spring after a forest fire has burned off the dead vegetation thereby releasing a host of minerals so that they're available to spur regrowth. The difference here being that the energy that's released in the heat of the forest fire is captured by the worms and turned into food for our fish, ducks and rabbits.

Phoenix worms

     Our initial work in this area has been with the traditional earthworm, and Vermadise is so named because that structure was designed to optimize its utility as a place where we can grow out a large quantity of earth worms both to enhance our gardens and produce feed for our animals. Producing our own feed isn't just a matter of economics, although that is an important consideration, but first and foremost it's something which we have to do in order to insure the integrity of Windward's ecosystem. Store purchased feed is often laced with commercial preservatives and anti-biotics, materials which we want to exclude from our food system--by compounding our own feeds, we retain control over what goes into them, and ultimately, into us.

     But earthworms are only part of the story--they're great for dealing with plant matter, but they're no use in dealing with offal and kitchen scraps. When you process a fish, chicken or rabbit for food, you're only going to see a yield of about half the live weight in edible meat--the rest is offal and has to be disposed of in some way. This is where phoenix worms (the larva of the Black Soldier Fly) come in. They're voracious critters that will consume anything from a spoiled potato to chicken guts in a remarkably short time. Depending on how much they're fed, they can go from egg to maturity in as little as two weeks and as long as six months.

the inside of the warmerator

     The only notable problem in utilizing these critters lies in getting over the "Yuck!" factor that is almost everyone's initial reaction to dealing with the larva of any fly. We understand--creepy, crawling things aren't cuddly like a rabbit, or funny like a duck, but they're very important parts of the natural cycle and something which we need to learn to appreciate and facilitate if we're going to create a critical mass of sustainability here at Windward.

     One of the key steps in creating a sustainable garden involves cultivating a population of beneficial insects so that natural systems keep the pests in check. Instead of purchasing deadly chemicals that will reak havoc on the garden's ecosystem, we use a range of techniques such as including plants that provide homes for insect predators to the inclusion of ducks that patrol the garden looking for insects to gobble down.

     In a similar vein, our goal is to build an indigenous population of Black Soldier Flies since they're death on the ordinary housefly. Since BSFs don't have a mouth (their lifespan is three days in which they mate, lay eggs and die), they can't spread disease the way houseflies can, and once they establish themselves in an area, houseflies won't even try to compete.

     Once the heat of summer was past, we were able to order a live shipment of phoenix worms and start the process of learning how to incorporate them into Windward's ecosystem. Since Vermadise isn't fully winterized yet, we were concerned that the recent snap of cold weather might kill our newly arrived worms, so we decided to use the warmerator to provide them with a cozy home for the time being as they bulk up to the point where they'll be able to keep themselves warm at night.

[Note: the warmerator is an old refrigerator that's rigged with a thermostat, fan and light bulb/heat source so that it's capable of maintaining a constant temperature. It's something that comes in real handy for all sorts of uses from making soap or yogurt, to sprouting wheat in the winter time.]

Phoenix worms doing their thing

     The warmerator is currently located in the freezer room, so it's quite convenient to drop off the kitchen scraps after the noon meal, and in just the first week the volume of phoenix worms has doubled. Being used to watching things slowly decay in a standard compost pile, it's quite remarkable to watch the phoenix worms at work. Each day the previous day's scraps are gone and the worms are clearly ready for more. At this rate, as soon as Vermadise has it's southern wall finished, our colony of phoenix worms should be large enough to transfer to their new home.

  November 11:

     The phoenix worms have been making themselves quite at home in the warmerator, and the total volume of worms has more than doubled since they arrived at Windward. Now that Vermadise is pretty much closed in, today seemed like a good day to make the transfer.

     Phoenix worms are, naturally, cold blooded, but they give off a remarkable amount of heat, enough so that once a critical mass of worms is reached, they should be able to keep themselves warm so long as they're working under an insulated cover.

     The containment we're going to be using for this first batch of worms is a modest-sized chest freezer. One of the jobs that Intern Sarah took on this summer was to wire brush the inside and outside to remove any light rust, and to give it a good coat of Rustoleum paint. She did an excellent and thorough job on a task that was rather tedious, and we think appreciative thoughts of her often :-)

     At this point, the worms and the kitchen scraps they're working on take up about three gallons of space, not enough to cover the bottom of the freezer to more than about an inch in depth so we just poured them into the middle and figured that they'd work out how far they wanted to roam from the pile for themselves.

the worms are tucked away under the blue foam insulation

     The next step was to cut a section out of a 2" thick sheet of foam so that it just fit inside the chest freezer. It's a fairly snug fit, but loose enough that it won't be a problem to lift each day in order to add the latest bowl of kitchen scraps.

     When the phoenix worms are warm, they've very active, but as soon as they cool down, they "freeze" and remain dormant until things warm up again.

     Now that there's a goodly mass of them tucked in there under their foam "blanket," our hope is that they'll be warm enought to keep processing the scraps into ever larger worms right through the winter. We'll keep you updated as to how that's working out.

  November 12:

     The temperature in Vermadise got down into the high thirties last night, but the phoenix worms did okay in their new home. When I lifted the foam insulation this afternoon, most of them were balled up in a mass in the center keeping each other warm. I decided to add more material for them to work with, as much as a way to increase the thermal mass as anything, and so I added in about three gallons of horse manure. It's not as desirable for the phoenix worms as it is for the earth worms, but it will provide them with more space to burrow in and keep warm.

the worms after their first night in their new home

     The weather report was suggesting that we'd see our first bit of snow this evening (correctly, as it turned out) so I was concerned that the phoenix worms might need some supplemental heat. I know that they go dormant when they get cold, but what I don't know is how they'll react to below freezing temps.

     They're established in Portland which is 173' above sea level and surrounded by the Columbia and Willamette rivers, but not here where the winters are colder. That raises the question of how much protection they'll need in order to over-winter here, something we'll learn in time. But for now, the goal is to keep them active enough to keep up with the kitchen's production of scraps.

  November 30:

     Well, I'm delighted to report that our colony of phoenix worms has made it through the first really cold weather of the season, and not only that, some of the larva have reached the stage where they're ready to pupate.

     One of the challenges of working with Black Soldier Flies is that they're so harmless that there's not been a lot of interest in paying attention to their breeding habits, so we're having to learn as we go. So far, all the lessons have been the nice kind--something which isn't to be taken for granted when dealing with natural systems since nature has its own agendas, and nature always bats last.

pupates hiding under the freezer lid

     When one of the larva decides that it's big and fat enough to pupate into an adult fly, it clears out its gut and starts a trek to find a safe and private place to pupate in, and these guys are famous for their ability to climb a 45° ramp up and out of the holding area.

      Indeed, it's this self-selection process in which the mature worms separate themselves from the worms that aren't yet ready that makes them a better choice for processing food scraps into critter food than earthworms which have to be sorted out by hand according to size.

      We're over-wintering the phoenix worms in a chest freezer that's being heated by a 40 watt lightbulb. That was enough to hold the inside of the freezer at between 40°F and 45°F even when the over-night temp outside dropped into the mid-teens.

     That's not as warm as the worms would like, but we're learning that there's a convenient linkage going on in that the worms respond to the odor given off by rotting food, and while the chest freezer isn't warm enough to get the worms really going, that's okay because it's also not warm enough for the kitchen scraps to rot. So, the upshot is that will the food scraps are building up in the bottom of the freezer, that's okay since the scraps are so cold that they're not rotting. One of the key things we're wondering about is whether this system will give off unpleasant smells--so far the answer, I'm happy to report, is, "No."

for scale, a single pupate in hand

     When I lifted the freezer lid today to check on the worms, I was surprised to notice that dozens of them had reached the "time-to-pupate" stage, and left the company of the other worms to tuck themselves in between the lid's rubber gasket and the top of the chest freezer.

     Somehow they had climbed up a good two feet from the mass of worms in the bottom of the chest. I don't know if they were happy there, or if that was as far as they could go before the cold, outside air chilled them to the point that they went dormant, but either way they were easily collectable at that location.

     I don't know how the larva feel to the touch, but I can report that the pupates don't really have much of a "feel" to them at all. They're perfectly dry, have a bit of heft to them and generally "OK" to handle. At this point we'll just store them away until Vermadise warms up to the point where they can emerge, mate and lay eggs to start the next batch of phoenix worms.

     I'm presumming that if you're still reading along, you're fairly interested in learning more about these magical worms. One of the best sites for doing that is The Bio-Conversion of Putrescent Wastes a slide presentation prepared by Dr. Paul A. Olivier. It's well worth watching.

Notes From Windward - Index - Vol. 66