Worm Composting: A Creative Way To Better Soil.
Worms simply don’t get the credit they deserve.
Sitting at the very bottom of nature's social ladder (well beneath it actually, six inches in the ground), worms are a true beast of burden as they do all the work but get none of the credit.
If we truly understood the power and necessity of worms, they would be celebrities, thrust onto the red carpet and crowned as our slippery and slimy masters. We would admire how they ceaselessly churn our ground into precious soil that is of utmost necessity to our plants, fruits, vegetables and subsequently, our human livelihood. So for that, worms, we see you, and we thank you.
This spring, as we harvest our goodies out of the ground and place them in our pots, let's remember to give back to these limbless laborers by including them in our best, most effective way of sustaining the soil…
What is Worm Composting?
Worm composting is also known as Vermicomposting. It is the process by which raw scraps of uneaten food are fed to, and thus broken down by the Red Wriggler (Eisenia fetida) variety of worm to create a nutrient-rich form of fertilizer.
As the worm consumes large, complex assortments of organic material (like kale stalks, apple cores, etc.) its body digests and excretes the elements into simple, dark, very small pieces of soil-like bits called castings. With the help of microscopic organisms, these castings are processed so finely that a plant can easily take in the accessible nutrients that were once locked away in a piece of vegetable far too large and complicated to be consumed by its roots.
Why Worm Compost?
Worm composting is not only good for the garden but also a better, more efficient use of resources.
According to a 2018 EPA report, it is estimated in the United States that 63 million tons of food was thrown away and transported to landfills. This number makes up 21.9 percent of ALL solid waste generated by municipalities alone.
While not all of this wasted food is compostable, the compostable portion is food wasted nonetheless.
When food goes to a landfill, it is buried and neglected, broken down very slowly without being exposed to oxygen. This process, known as anaerobic fermentation, produces immense amounts of methane- a robust greenhouse gas 26 percent more potent than carbon dioxide.
In comparison, when our worm brethren do their earthly duty to compost, they contribute to the process of aerobic decomposition, which exposes the compost to air where the carbon is used by microbes to generate heat and limit the production of climate changing gasses.
Worm Composting Benefits.
Where all compost is good compost, worm compost is an easier way to recycle organic material, as it doesn’t require constant churning or management of material ratios.
It lets the worms do the work!
It also saves space and reduces odor. Unlike traditional compost which needs the space to be churned and can often begin to smell, worm composting (if done correctly) has a much less penetrating fragrance and requires very small amounts of space for worms to do their jobs (they’re just little guys after all).
People also often claim that worms compost faster than traditional methods, however this is dependent on the materials being used. If a lot of large vegetables are being given to too few worms, the process can potentially take much longer (six months or more). However if food is made ideally consumable for enough worms, like chopped into small pieces before depositing, then the process is much faster (six to eight weeks) and rivals if not beats out traditional composting times.
Differences Between Worm Composting and Traditional Composting.
Conventional composting is considered “hot” where worm composting is “cold.” When compost is made by microorganisms alone, the decomposing materials develop an increased temperature as bacteria thrive and generate heat. This heat, along with oxygen and moisture, create a sophisticated ecosystem within an environment that requires a level of checks and balances to remain functional.
Worm compost does not produce excess heat as part of its natural cycle.
This means that worms have a greater sensitivity to outside temperatures, it also means that any seeds that end up in compost are not sterilized by high temperatures and can potentially germinate if not removed beforehand.
Worm compost does benefit from some micro-organic activity, but most of the “dirty work” is done by the wrigglers.
Due to the heartiness of the worms, the worm compost is less delicate internally and requires less maintenance. Where worms will not thrive in extreme exterior temperatures, they will survive mild frosts and high heat while needing much less from their human hosts than the regular veggies they love and crave (however they will certainly slither and work slower in the cold).
Worm compost also on average produces more nitrogen than traditional compost, some studies citing up to a 4 percent increase.
Where To Start.
There are multiple ways to start a worm compost. The most common way is with a bin, for a main benefit to worm composting is the space saving qualities and a bin is the best way to take advantage of this.
Henry however, has opted to incorporate his worm compost as part of his backyard homestead that composts the unused vegetables used to make all of the FFTS meals, including Lentil Walnut Pilaf With Kale and Zesty Miso Broccoli Slaw, so we will take a look at that as well.
Whether using a bin or an outdoor pile, you will need to start with the same materials:
- A container or area for compost.
- Biodegradable bedding.
Bin or area for compost.
For bins, a variety of materials can be used. Styrofoam, plastic bins, and non pressure treated wood are all fine options. Worms are sensitive to light, so it is best to make sure that whatever container utilized is not transparent.
Henry, as seen here, has built a backyard container using heat treated softwood pallets. It is exposed to natural daylight and as the sun shines the worms burrow deeper. This is a natural process that makes good use of outdoor space but may in turn slow down the decomposition process. It also requires more effort to churn and bury composted material.
The benefit for Henry is that his vermiculture area is next to his chicken coop where can transfer nitrogen rich droppings into his compost.
Generally, worms thrive at temperatures between 55 and 77 degrees Fahrenheit. When choosing an area for a bin, they do well in pantries or cupboards, for a properly managed bin is odorless. In outside conditions, placing one in the shade is ideal in order to prevent too much temperature fluctuation.
Ventilation is key, so a lid with holes and mesh will help keep rain out and the air flowing. An outdoor system like Henry’s does not repel rain but does allow drainage. A bin however, does not drain and must be kept dry, so putting it in an area where it is not exposed to direct rain is best. It is also good to keep in mind that a container full of food scraps will be quite tempting to any meddling little critters, so placing the bin somewhere protected from them is also recommended. For an exposed, outdoor compost like Henry’s, chicken wire is a good method to help repel animals.
In order to strike the best balance for nurturing both worms and anaerobic bacteria in a bin, 8 inches to a foot soil depth is recommended. Red Wrigglers are actually shallow surface dwellers, typically thriving no more than 6 inches beneath the soil. Aerobic bacteria thrive in about this same depth, as anything below about a foot begins to limit the oxygen ideal for the survival of these microscopic munchers that help the worms process veggies into vermicompost.
Once again these are for absolutely ideal conditions. In Henry’s personal backyard setting, the compost pile is quite deep and the worms thrive at the depth they prefer, often relocating to warm spots in the soil while moving towards sources of food. Henry often turns his compost to help aerate the layers and to help mix in added material.
For bedding, there are several different materials that work well. The most common that may be lying around the home are newspaper and cardboard. When this material is cut or torn into little bits and laid 8 inches deep in the bin, it creates a nice and easy medium for the worms to glide their little bodies through to food. The material needs moisture as well, around 75 percent moisture actually, or to the point where the bedding feels about the same as a wrung out sponge or wet towel (its ok if its not exactly 75 percent, just make sure the material is wet but that the worms aren’t going for a swim).
Other good materials include:
- Coconut Coir
- Torn up or partially decomposed leaves
It is better to mix at least a couple of different materials together to help the bedding retain some loft and to help soak up moisture.
When the bedding material is ready, it's best to add some abrasive material (grit) to the mix. Worm bodies use a gastric mill (gizzard) to digest food, and therefore require grit to help grind up food particles in the stomach. Good materials for grit include:
- Crushed shellfish shells
- Crushed peanut shells
Add a handful of material every couple months to aid worm digestion.
Curious about how worms do their thing? Check out some worm info and anatomy here.
Adding the worms.
It's time to introduce our hungry heroes to their new home.
For the amount of worms needed, the answer varies by size of bin and system. For a standard size bin of around 22″ L x 16″ W x 6,” a thousand worms will thrive just fine. Around a pound of worms per square foot of bin space will usually do the trick.
Uncle Jim's Worm Farm is a popular source for different breeds of worms.
When adding the worms, it is perhaps best to add them together with some partially decomposed food scraps so they have something to snack on. It may take a few days for them to adjust to their new environment, and some worms may perish in the process. Worms are tough little buggers, however, and shouldn’t require more than some check-ups over the next few days as they get used to the new space.
Monitoring the amount of moisture in the bedding and making sure it stays wet (very moist but not dripping when a handful is squeezed) and keeping the bin at ideal temperature (between 57 and 77 degrees Fahrenheit) are the best ways to ensure their success.
Feeding the worms.
Worms love food. In fact, pretty much all they do is eat, poop, and discuss nineteenth century philosophy.
Ok, maybe not that last part.
When giving the worms what they crave, remember that this is not an all-you-can-eat buffet. Worms have preferences, and your soil does too. So when feeding them remember the do’s and don'ts
Worms really thrive when presented with organic material that isn’t too spicy, and it’s perhaps better to avoid feeding them smelly foods like onions, especially if the bin is inside. Meat and oily foods are a no go because of their smell and toxicity, and pet droppings often contain harmful parasites.
Fruits and vegetables are great, however it's best to be mindful of the amount of acidic foods like oranges or limes being put in the bin, for too much acid can be toxic to worms.
Also, if food is processed into tiny pieces before being placed in the bin, the worms will compost them much faster.
Begin by adding about ½ a pound of food scraps per pound of worms and see how they take it. If the same food remains in the bin after 2-3 weeks, chances are the worms are being overfed. The warmer the bin up to 77 degrees Fahrenheit, the faster the worms will eat and multiply.
Food can be added and stirred around in the soil to integrate it, or a more controlled method is to add a layer of food to the surface of the soil (about an inch deep) and then to cover it with a thin level of fresh bedding. With this method, the worms will migrate up toward the food and leave the lower layer vacant, making it easier to harvest it later. In addition, when worms travel in a linear direction, it helps aerate the soil and promotes better decomposition and less odor.
Harvesting the compost.
After about 3 to 6 months after initially starting the bin (when the compost becomes dark and crumbly and smells like fresh soil) it is time to begin the process of separating the worms from their soils.
There are a few ways of harvesting the compost, but one of the best ways is to use to your advantage the power of the thing that annoys the worm more than anything else: the sun.
When the compost is dumped onto a reflective tarp and sorted into small piles to dry out in the sun, the worms will retreat away from the light into dense, collected balls in the center of the piles. Here they can be isolated, and the rest of the soil can be cleanly brushed away.
Some worms may die, and some compost may cling resiliently to the worm cluster, but regardless of worm or soil loss this process remains as one of the most effective ways of harmlessly separating them.
When the compost is removed, the remaining wrigglers can be reinserted into a fresh bin of bedding and organic material.
With Henry’s outdoor system, he uses what is called the “bait and switch” method, where fresh food is loaded into one side of the compost bin, and over the course of a week or two the hungry worms naturally migrate toward their veggie delights, thus freeing up their previously inhabited soil for the taking. This method works with bins as well, where food can be pushed to one side of a bin to redirect a worm population away from the soil to be collected. Bins can even be designed and drilled to stack on top of each other so that the worms journey from bin to bin as fresh food is deposited into the upper levels.
This way, soil on lower level bins can be collected and the wrigglers remain happy and undisturbed in their paradise of darkness and decomposing greenery.
Happy Worms, Happy Garden.
There you have it. If worm farming is cool, consider yourself Miles Davis, as you now have all you need to start a prosperous relationship with the real kings of black gold.
After building a worm bin, it's best to keep a close eye on it for the first few weeks for this is when the worms are most vulnerable to potential failure. The key here is to be strict about monitoring the moisture of the soil, ensuring the interior of the bin is absolutely dark, and making sure the worms have enough of the right food. When in doubt, leave it out, as anything questionable could do more harm than good to these sensitive crawlers trying to adjust to their new environment.
Once the worms are “grounded” in their new home, they are mostly maintenance free. Worms are ultimately a tool for cold composting that requires less routine than a regular hot compost. With that in mind, if more time is invested in the bin’s initial creation, less time will be spent later on as all that the worms will need moving forward is regular feeding.
Most problems with bins come from an imbalance of moisture, food, air and temperature. If pests appear or worms perish, it is likely due to one of these factors.
Worms are tough buggers though, so for the most part they will happily churn through their compost casa without much pampering.
As with any system, there is a method that works best for those who wish to experiment, so there are certainly ways of worm composting here that aren’t mentioned that may be most suitable for a particular garden, and with that its always a good idea to try new things to see what works and what doesn’t.
For all those gardeners and growers out there looking to bring some life to their loam, worm compost is both a creative, easy and compact way to do so. A worm bin takes less than an hour to make, and when done correctly, is a fun venture into nurturing life and health within what is arguably the most important part of an ecosystem- the soil.