Worm Bedding
Before we discuss the various materials which are suitable for this purpose, and the advantages or disadvantages inherent to each, let's take a moment to decide what we are trying to accomplish by providing the worms with bedding in the first place. We can do this by looking at what the worms need in order to lead healthy and productive lives, and then deciding which of these needs are dealt with most efficiently by the bedding.
A Worm Needs....
- Food to eat.
- Environmental conditions free from rapid fluctuation.
- Shelter from light sources.
- Access to potential mates. And...
- Delicate handling.
Now if we only had the worms to consider, that would just about do it. However, when we talk about cultured worms, we must also consider the needs of those who are doing the culturing, namely you and yours truly.
A Vermiculturist Needs....
- Healthy, productive worms.
- Freedom from foul-smelling bins.
- Freedom from intrusive pests. And...
- Easy access to required materials.
- (A winning ticket in the local lottery is probably out of the question?!)
With that in mind, we can now set down at least a couple of basic qualifications for what makes a good worm bedding. Though these are not the only considerations by any means, these points will go a long way to setting us on the right path.
Bedding Material Should....
- Retain moisture in a form that is accessible to worms.
- Stay loose and allow for air passage between the individual particles.
- Allow for drainage of excess moisture.
- Not be coarse enough to damage a worm's delicate skin.
- Not be a food source that is high in protein.
- Be aged past the heating stage. And....
- Be free of topsoil. (Red worms are compost or manure worms as opposed to earthworms.)
So, with all of these points in mind, let's get down to the job of looking at the available options, and the various pros and cons associated with each. Just before we do, however, I should point out that I am not trying to nudge anyone in one specific direction or another. All I am really interested in is giving everyone enough information so that they can decide on whichever bedding will best suit their individual circumstances, and a pointer or two on how best to use whichever one they finally decide upon. Each of the following materials are suitable as worm bedding, but some will simply be more suitable than others for your particular needs. So if that is clear to everyone.....we may proceed.
Worm Bedding 2
Peat Moss

With the exception of manure (a topic we will deal with in a later article), peat moss is probably the most widely-used of all the worm beddings. A few years ago, we could even have defined this material more specifically as "Canadian" peat moss, or sphagnum moss. The reasons for that particular preference had to do with the fact that the Canadian peat moss was a sterile medium, whereas the American peat moss was more likely to contain various impurities which might have proved harmful to the worms. Though many breeders still ship worms in Canadian sphagnum, often at the specific request of the buyer, if reasonable care is exercised, just about any peat moss may now be used.
Since I can already hear the multiple screams heading my way, let me explain what I mean by reasonable care. First of all, any suspicious moss should be thoroughly "leached" before it is used as worm bedding. This is a simple matter accomplished by soaking the material for a few hours (or overnight) in clean water, and then squeezing out the excess moisture. If the water you squeeze out is dirty, the process should be repeated until the resulting flow is as clean as when it was first added. At that point, resist the temptation to add your entire worm population to the moss until you have first allowed a brave handful of worms to try out the new accommodations for at least one entire night. If they survive, chances are the others will also. Of course, if you are fortunate enough to have access to some of the true Canadian sphagnum, you can probably skip the first step altogether, and proceed directly to the test with the partial population. I do, however, strongly suggest that you never skip the second test. You may get away with it 99 out of 100 times, but just one bad batch of moss and....well, you get my point.
Like most other bedding materials, peat moss has both advantages and disadvantages. The reason for its popularity, however, is that the advantages pretty much outweigh the negative aspects, and those things considered to be disadvantages can often be used in a positive manner. If we understand each of these characteristics, and make the best use of them, it becomes easy to see why so many worm breeders favor this material.
Among the advantages of peat moss can be found the following items:
Moisture Retention.
Because it retains moisture so well, peat moss can lessen the amount of daily attention required by the worm bed (a major plus in multiple-bed situations.) And less watering means you will have that much more time to teach the worms to dance, recite poetry, or run for political office. In all fairness, I have to admit I have heard at least one individual express concern that while peat moss does indeed retain large amounts of moisture, the water is trapped inside the fibres, where the worms cannot make use of it. I also have to admit that I find that a little hard to believe, since the worms ingest the entire fibre, water and all. If any worm has ever died of thirst while living inside moistened peat moss, I, for one, have never heard about it.
Cleanliness.
This is one of those characteristics you can only appreciate if you have had prior experiences with bedding materials that are not so easily handled, such as manure or leaf mold. Properly moistened moss is a pleasure to handle, and if you should drop a little here or there, just let it dry, and vacuum or sweep it up.
It Has No Inherent Odor.
Though worms tend to deodorize most materials simply by their existence within the medium, there is often a short period of time where some beddings might be just a little offensive to those of us with delicate sensibilities. No such problem with peat moss, a definite plus in my books.
Availability and Consistency
If you happen to live in a rural area, the availability of material for worm bedding should never be a problem. Urban living, however, can often present certain difficulties. Aside from having to gather materials, storing those which you manage to accumulate can present additional problems. For those with very limited storage space, or lacking suitable amounts of the time or inclination required to gather materials, peat moss offers easy access, usually at a reasonable cost. Any decent garden-supply shop will have this material on hand, and a medium-sized bag can usually be purchased for just a few dollars. For the average indoor system, a bag of moss will usually last several months, and if the same brand is constantly used, the worms will not be subjected to the rapid changes of condition that can so often raise their mortality rate.
Diversity
Last but not least among the advantages of using peat moss as a bedding material, we should make mention of the wonderful diversity of this substance. Not only can peat moss be used alone, but it can also be used to enhance just about any other bedding material, and even as a method of rectifying certain problems encountered with other products, and also some environmental problems. For instance, if a certain bedding material drys too rapidly, adding a 30-50% mixture of moss will help to retain the necessary moisture level. In beddings that are too dense, peat moss will add a little porosity, and in materials that are too far on the alkaline side of the pH scale, the acidic nature of peat moss can serve to bring things into a better balance. When used as a shipping medium, peat moss will retain enough moisture to cool the worms, without requiring so much water that it will easily freeze solid. The fact that this material is lighter than most will also save some of the shipping costs, and because of its sterile nature, you may encounter less hassle from Customs when shipping internationally. All in all, peat moss has a lot going for it, and eventually, just about every worm breeder or vermculturist will come to consider it an indispensable part of their operation.
Among the disadvantages of peat moss can be found the following items:
The Cost.
Now I know I already said that peat moss was inexpensive, and it is (as long as we are talking about a regular-sized indoor operation.) However, many other bedding materials are free, so we have to be fair and call any price-tag at all a disadvantage. In the situation of a larger set-up, the cost can rapidly add up, and for commercial applications, the expense would be simply ridiculous. What this means is that peat moss is a great choice for an indoor bedding for a regular-sized set-up, but can only serve very specific needs for anything much larger than a one or two-bed system.
Its Acidic Nature (pH)
By its very nature, peat moss is an acidic substance. Since the worms prefer a pH that is close to neutral (or very slightly acidic), this can present a problem if certain precautions are not taken. First of all, worms that were previously housed in bedding materials that were neutral or slightly alkaline, should never be transfered directly into straight peat moss. Though I have raised several batches of worms in sphagnum (moss), they were either hatched initially in that substance, or gradually acclimated to the new conditions. To acclimatize worms to new bedding, I simply transfer an amount of the old material, worms and all, to one side of the new bed, opposite to the fresh bedding. The worms will then move into their new environment at their own pace, and the number of casualties is considerably reduced. (This procedure should be used whenever you place newly-received worms into a bed that contains material other than that which they were shipped in.) On the plus side of this matter, the acidic nature of peat moss can be used to balance other beddings (or soils) that have become too alkaline for whatever reason, something that gardeners everywhere have known for years.
A Lack of Nutritional Value
Since peat moss is made up of very old plant matter that has been sitting in, or under, a bog for many, many years, whatever nutrients it may have contained in a previous lifetime (spooky, huh?) have all been thoroughly leached out, which means that not even a worm can live on a steady diet of this material for any length of time. As far as that being a disadvantage or not, I guess it's merely a matter of personal opinion. If you are more interested in getting rid of food scraps (or some other feed source), rather than peat moss, you might consider this to be a benefit, since the worms will rely on the feed for nutritional value, and the peat moss will add body as it gets blended into the final mixture. This tendency to add to the structure of the finished compost is one of peat moss's best selling points, so maybe this item should have been listed under advantages after all. (Too late. )
All in all, a truly remarkable substance, and as we've already stated, a bedding material widely-used by vermiculturists around the world.
Worm Bedding 3
Bog Soil
Though this material has a lot in common with peat moss, it must be understood that bog soil is a very different substance, with unique characteristics of its own. When we refer to peat moss or sphagnum, we are usually speaking about dead plant material that can still be identified as such. Bog soil on the other hand, is material that has been dredged up from the bottom of the bog, and is decomposed well past the stage where easy visual identification is possible. As opposed to peat moss, which is usually brown in color, bog soil that has any moisture content at all will be very black, turning slightly brown only when completely dehydrated.
During the period that I was maintaining my worm beds in Prince Albert, Saskatchewan, I was directed by a customer of mine to a bog located just outside of town. (It was one of the nicer places I have ever been told to go. ) When I arrived at the site, I discovered that at some point in history, someone had dredged mountains of material from the bottom of the bog, and left it piled up in huge mounds all around the edges of the water. I suspect the absence of sufficient quantities of sphagnum was the main reason the "bog soil" had been abandoned. At any rate, the place was open to public access, and there had obviously been many people before myself who had loaded up large quantities of this material, probably for use as a soil additive in their gardens. For several months after that time, I periodically trucked a load of this "soil" home, screened the larger pieces of wood out of it, and used it as worm bedding. The worms loved it, and it made a really nice final product after the worms had mixed it with all the food wastes I was using as feed. (Finding a beautifully-preserved piece of fossilized tree bark in one of the batches I took home was also a very pleasant bonus.)
Among the advantages of bog soil can be found the following items:
Moisture retention.
This is one of the areas where bog soil is very similar to peat moss, holding several times its weight in moisture content. In fact, it seems to me that it might be even better than peat moss in at least one regard. Though I've never run actual tests to determine by how much, I would have to say that bog soil holds the water even longer than moss, apparently being more resistant to the effects of evaporation. Also, peat moss will tend to "crust" over at the surface as it loses moisture, but bog soil remains friable even when its dry. This allows the worms better access to the surface, with less chance of damage to their skin.
Lack of Odor.
Another similarity shared with peat moss, but beneficial for at least one reason in addition to the obvious one of not being offensive. When you use peat moss, it is easy to estimate how converted the bedding has become simply by watching the color of the material. As the level of the castings increases, the bedding will become darker in color, alerting you to the fact that a cleaning of the bed might be in order. Since moistened bog soil is already black, however, it requires a pretty good eye to tell what percentage of castings the bedding contains. (A close inspection will show that the converted material is slightly lighter in color than the fresh material, a dark grey as opposed to black.) This is where the initial lack of odor becomes very important. Since worm casts contain a large amount of actinomycetes, and actinomycetes account for the smell associated with good rich earth, we can let our noses substitute for our eyes. If we sniff a handful of the bedding material, and the bog soil now smells like fresh garden soil, we know that a fair amount of conversion has taken place. Like all casting-rich bedding, if you completely dry an amount of converted bog soil, it will turn in color to a light grey, quite easily distinguished from a sample of the fresh material.
Diversity.
In this area, bog soil shares the same benefits as peat moss in that it can be used to enhance other beddings that do not hold moisture as well, and it can still be used for its cooling properties, and its lightweight nature, though in all fairness, it weighs slightly more than moss, and packs a little tighter. In these areas, I would rate bog soil as a strong runner-up to peat moss, and way ahead of the remaining materials.
pH.
In the matter of pH, I consider bog soil to be superior to peat moss, since it tends to be a completely neutral substance. Of course, this means it cannot be used to correct the imbalances of another bedding, but that disadvantage is far outweighed by the benefit of its neutrality. Since it is neither acidic nor alkaline, worms can usually be transferred into this bedding with very little risk to their well-being.
Cost.
Whenever you can find this material, it will probably be free for the hauling, and that's a price you simply can't beat. A couple cautions, however, might be in order. First of all, always respect private property. Some bogs might be located on privately-owned land, and in that situation, either permission should be sought from the owner before removing any material, or the site should be removed from your list of locations. With all the many sources of bedding material which are available, trespassing is not only unnecessary, but very likely to give vermiculture a black eye which it simply doesn't deserve. Another point to keep in mind is the possibility of obtaining contaminated material. Though it is sad to say, the truth of the matter is that bogs have often been used in the past (and probably still are in the present), as illegal dumping sites. If the bog you are considering happens to be in the immediate vicinity of a large mill, or industrial site, you might want to look elsewhere. It would be a shame to produce castings that were later responsible for the contamination of your garden, or possibly the illness of your friends, your family, or yourself.
Among the disadvantages of bog soil can be found the following items:
Availability.
Since bog soil is basically an unprocessed material, you are very unlikely to find it in your local garden center. Even if you have a vehicle, and the ambition required to find a suitable source--a bog that is open to the public--there is still a fair amount of work involved in loading it into containers, and then unloading the containers upon arrival at your home. It will also require screening to remove the larger pieces of wood which always seem to be present, and finally, if the trip is to be made worthwhile, a large amount of this material will likely need to be acquired. The storage of this excess material until it is needed could present some problems of its own. In short, if your particular circumstances are not just right, acquiring this material just may not be worth the effort.
Possible Contamination.
We have already discussed this possibility a little earlier, but I wanted to mention it once again, simply because it is so important. I cannot stress it enough. If you have any reason to suspect the integrity of a batch of bog soil (or any bedding), find another source! There is simply too much material available for use to have to settle for something that may prove to be harmful to the environment (I include people in this word since we certainly are part of that environment.)
Lack of Nutritional Value.
(See comments under same heading in section on peat moss.)
All things considered, and all cautions taken, bog soil is an excellent bedding, and anyone fortunate enough to come across a good, reliable source of this material should consider themselves to be very lucky individuals indeed.
Worm Bedding 4
Newsprint

Now this is a material you just have to love. Not only is it relatively easy to use, and as plentiful as it gets, but using it as bedding solves the problem of bundling it up, and lugging it off to the recycling depot. Which brings me to another point, and my first real digression in this article (I really am getting better. )
In the time that I have been vermicomposting, I have been subjected on at least two separate occasions to lectures about the evils of feeding paper products to worms, when in fact I should be recycling those materials. The somewhat distorted logic at the heart of these lectures goes something like this. It is better to reuse a material several times than to feed it to worms once, whereupon it is forever lost to the world?! My personal view of that particular argument is best expressed in this manner.
First of all, material that is fed to worms is not lost to the world, but rather, it is transformed into one of the finest soil additives available to us from anywhere. Using this material in places such as tree nurseries can result in faster-growing, and even healthier trees. More trees equal more material for not only paper products, but building materials, and even other considerations such as food, air, and natural beauty. So vermiculturists are not taking something away from Nature, but in actuality, adding to it. And as far as the paper recyclers go, consider this. Even with the popularity of recycling these days, the process is still in its infancy. The truth of the matter is that the entire recycling industry is diverting just a fraction of the available waste materials from the landfills and incinerators of this planet. If we can feed another fraction of that particular part of the waste stream to our worms, fine. And if we ever reach a point where no more material is being landfilled, and the recycling industry cannot find enough paper to process, we can always switch our worms over to yard wastes, food scraps, or other such materials. In the meantime, we are only dealing with a portion of the material that is beyond the capabilities of a very young recycling infrastructure. (We are your allies, not your enemy.) And now, back to the business at hand.
Among the advantages of newsprint can be found the following items:
Availability and Consistency.
Newsprint is one of the most common materials available anywhere in North America. If you yourself don't receive a daily paper, you probably know many people who do. With only one or two of those people saving their papers for you (and being grateful to get rid of them), you can keep most in-home worm bins in perpetual bedding with no effort whatsoever.
Easy to Use.
Whereas certain bedding materials require a fair amount of preparation prior to use, newsprint needs only to be shredded and soaked. The excess moisture is then squeezed out, and the bedding is ready for use. Hand-shredding is probably the most common method of reducing the paper in size, with paper-shredders rapidly becoming more popular. Though newsprint can be ground into dust with larger industrial machinery such as a hammer mill, this results in the need of wearing protective devices to prevent the accidental inhalation of the finer airborne particles. (You don't want paper-dust in your lungs.) Since moist newsprint decays quite rapidly even in slightly larger pieces, however, reducing the material to the size of dust is really unnecessary. You could also decide to simply crumple up entire sheets of moistened newsprint, but then expect it to take a little longer to get eaten.
Cost.
As I have already mentioned, newsprint is readily available, at a very reasonable cost, or free. If you find you require a lot of this particular material, you might try approaching your neighborhood grocery store, and inquiring about how they dispose of the daily papers that do not sell. Often, you will discover that just the banner portion of the front page is saved as proof that the paper was not sold, and the rest of the paper is then cast into the garbage. Usually, a store owner would prefer to have someone pick up these unwanted items, rather than have them added to the garbage which he/she will later have to pay to have hauled away.
Convenience.
Any time you can arrange to have your worm bedding delivered to your door, rather than having to go out and locate it elsewhere, you can consider yourself ahead of the game.
pH.
This time I'll list the matter of pH as a benefit, which is where it probably belongs at any rate. Like peat moss, newsprint is naturally an acidic material, and as such, it also may be used to bring overly-alkaline substances back into balance. (Once again, gardeners have known this for a very long time.) Since it is acidic, however, the same cautions must be taken that were mentioned in our discussion of peat moss' pH, and the same methods should be used when worms are transferred into newsprint from a bedding that falls closer to the alkaline side of the scale.
Among the disadvantages of newsprint can be found the following items:
Possible Contamination.
This point is one that should never be neglected, but one that may also prove very tempting to those of us who find we have very little time which we can devote to bedding preparation. I'm talking about considering the use of newsprint that has already been pulverized for use as an insulation material. To put it plainly....DON'T DO IT!
Newsprint that has been prepared for use as insulation has also been treated with fire-retardant chemicals. Not only could these chemicals destroy your worm population, but even worse, the worms might actually survive, producing castings that could later be used to fertilize your garden, possibly contaminating a portion of your food supply. In short, saving yourself a little effort is just not worth the potential risk which it involves. For this same reason, machinery that has been used in the preparation of insulation should never be used to prepare bedding material.
It Drys Rapidly.
Unlike peat moss, or bog soil, substances which hold water extremely well, newsprint that is exposed to the air loses its water content quite rapidly. The key phrase here is exposed to air, and as long as we keep this in mind, the problem is easy to solve. What you want to do is place at least a couple of inches of a more water-retentive bedding (such as the already-mentioned moss or bog soil) on top of the newsprint, creating a barrier from the air, and resulting in a lessened need for watering. It is important that newsprint bedding remain moist, since it becomes very rough when it is dry, and this could cause a problem for the worm due to its delicate skin.
It Leaks Light.
Depending on whether you shred the newsprint, or simply crumple it up, a certain amount of light may filter into the lower regions of the bed. If we understand that a worm does not flee the light due to some unreasonable fear, but rather due to the fact that it is sensitive to ultraviolet rays (prolonged exposure to a light source will result in the death of the worm), then we can understand that this is not a good situation. Once again, however, a top-covering of peat moss, bog soil, compost, or manure can easily be used to solve the problem. A piece of dampened burlap will also work, but a top layer of another bedding material has an additional benefit, which we will discuss very shortly.
It Can Become Compacted.
This is another area where the degree of the problem will depend on the manner in which the newsprint was prepared as bedding. If shredded, rather than crumpled or pulverized, newsprint can become quite packed down, resulting in several situations which need to be considered. First of all, compacted newsprint is not the easiest material to bury a feed source into, or harvest worms out of. If this was the only problem, however, that good old top-layer of a different bedding material would once again solve the problem. That is the additional benefit I mentioned earlier, a more friable bedding material for the worms to use while the newsprint has some time to decay. However, there is a more serious problem that could develop which a simple top-layer cannot prevent. If the bedding becomes so packed down that it cuts off the available air-supply, anaerobic bacteria (which thrive in the absence of air) could rapidly invade the worm-bin, resulting in the same aroma that a garbage bag produces when built-up fluids drown the bottom layers of the waste material. Not only is this an aroma you will really want to avoid in your house, but the worms like it even less than you, and will probably desert the bin, setting off in search of a more suitable area to live in. This will probably result in great unhappiness for you, and a very quick death for the worms.
At any rate, if we consider all the positive points involved in using newsprint as bedding, we can see that it really is a very useful material with a lot going for it. On the other hand, there are also several negative aspects which must be taken account of, if we wish to avoid creating more problems than we are solving. With all of that in mind, I usually recommend that people who wish to use newsprint as bedding, do so in the following manner.
Reduce the material to the smallest size that is reasonably possible, then use it as only one ingredient in a bedding which is composed of several different materials. In that fashion, the newsprint can be used to compliment various other beddings, and at the same time, the other materials can help eliminate the chances of encountering one of the problems most often associated with using the newsprint all by itself. I personally consider newsprint to be a vital ingredient in several of my own worm-bedding mixtures, and appreciate it as a truly beneficial substance.
Worm Bedding 5
Machine-Shredded Paper
With machine-shredded paper, we come to one of the most neglected, yet plentiful sources of worm-bedding material. In every populated area of the modern world can be found office-buildings, libraries, schools, police stations, and countless other locations that have in common the fact that they produce amazing amounts of waste paper each and every day. A tremendous portion of this paper is simply shredded, placed into plastic bags, and sent off to the local landfill. All it usually takes to obtain this material is to ask the office manager, the janitor, or whoever is in charge of the particular site, for permission to haul it away, and your bedding requirements are satisfied. (If you tell them it's for your worms, they may look at you a little strangely in the beginning, but that's something we should all be used to by now.)
For most regular-sized, indoor vermicomposting operations, one location will suffice to provide all the bedding that is necessary. Since the material is already shredded, the work-load is reduced to transporting the paper to your home, moistening the required amount, and installing it in the bed. By giving a little consideration to the "disadvantages" listed below, and keeping them in mind when you pick a location, you can have all the safe bedding your worms require, for very little effort, and you will be doing something that is environmentally friendly at the same time. For that matter, if enough in-home vermiculturists each absorbed part of the waste from one or more of these sources, it would not be long before a large amount of paper was being dealt with in a much more suitable manner than it presently is. In that situation, everyone is a winner. Just before we discuss the disadvantages, let's take a look at the more positive aspects of this potential bedding source.
Among the advantages of machine-shredded paper can be found the following items:
Availability.
As I've already stated, there is not a populated area in the world that doesn't produce large amounts of this substance. Aside from the sources I listed above, keep in mind any location that produces flyers, such as the kind that are stacked in grocery or department stores, informing patrons of weekly, or daily specials. Any government office is a pretty sure bet, as are local telephone, or utility companies. With just a little effort, I'll bet anyone can come up with a list of 10 or 12 possible sources of various shredded papers. And if you belong to any kind of group or organization that includes several vermiculturists, the purchase of a community paper-shredder might be an investment worth considering. (Choosing your own source of raw material to shred will help you overcome the most significant of the disadvantages involved in dealing with this choice of bedding.)
Consistency.
This advantage is reliant on the fact that you first find a suitable source, and then stick with it. If you are fortunate enough to find a location that not only produces safe material, but enough of it that you have no need to use an additional outside source, hang onto it by fostering a good relationship with the producer of the material. You are performing a service for them by eliminating a certain amount of their waste problem, and they in turn are doing you a favor by supplying you with a free source of bedding material. If each of you appreciates the efforts of the other, there should never be a problem. If the source you have found produces a large amount of waste material, you may even want to introduce the producer to another vermiculturist or two. The producer will see even more of the waste being taken care of, and you may also advance your friendships with your fellow wormers.
Cleanliness and Lack of Odor.
This is another of the substances that are usually a pleasure to work with. Though machine-shredded paper can suffer from the same smudging problem as newsprint (since that could be the shredded paper you find yourself dealing with), it is already shredded, so the problem is nowhere near as bad. Odors are never a problem, and as I've mentioned elsewhere, I consider that to be a major plus.
Cost.
What can I say? Completely free, unless you count the cost of hauling it, and if you choose your source wisely, transportation should never amount to much. Even if you put out the expense of purchasing one of the community-use shredders I mentioned earlier, the actual bedding material you can produce with it will cover your costs in a very short period of time. If you take into account the labor you'll save by not having to shred the paper manually, you may even agree that the machine is profitable in the literal sense of the word. (That depends on just how much bedding material you have a need for.)
Diversity.
Like peat moss, machine-shredded paper can be used to bulk up other bedding materials that are simply too dense. By keeping the bedding loose, the worms will be healthier, and maybe even happier, in addition to the fact that you are a lot less likely to encounter anaerobic conditions.
Among the disadvantages of machine-shredded paper can be found the following items:
Possible Contamination.
This point makes up the largest possible difficulty when using machine-shredded paper as worm-bedding. Furthermore, the problem (at least as far as I, or anyone I'm aware of, has been able to determine) lies not in the possibility of endangering the health of your worm population, but in the possible health risks to yourself, or your family, if a contaminated source of raw material is used.
The problem lies in the area of obtaining waste material that has been used in a photocopier, and the main area of concern is the toner used in the photocopy process. (Toner is the powdery ink substance used to produce a photocopy, and may be plastic, or chemical in nature.) Since very little laboratory research has been done in the area of problems caused by transferring these artificial substances into the food chain, we have no way of knowing what ill effects might be caused by ingesting food grown in soil that has been enriched with compost containing these substances. We can assume, however, that since a worm's diet consists strictly of organic matter, these inorganic materials are passing through the worm's digestive tract, and becoming somewhat concentrated in the resulting casts. (The same situation occurs with the heavy metals contained in some sewage sludges. After being consumed by worms, the result is less overall volume to dispose of, but higher percentages of contamination in the remaining material.)
Since we are talking about your own health, and the health of your family or friends, I think if a mistake is to be made, we should err on the side of caution, and at the very least, follow some simple precautionary guidelines:
If any bedding material in your worm-bin originated from a photocopier source, then the resulting casts should only be used in soil mixes intended for use in potted plants, and care should be taken that the above-mentioned potting soil is properly disposed of after use. This means taken to a landfill site, rather than being added to your garden. (Remember to also avoid discarding the used potting soil on your lawn, since ingestion by your neighborhood birds might simply result in a more roundabout entry of the contaminants into the food-chain.)
If you are unsure about the origin of the bedding material, then treat it in the manner stated above. And finally,...
If you are ever in a position to encourage, or support research into this area, (a simple letter to your environmental agency or university could go a long way), then please take the time to do so.
With all of that said, I still have to point out that we don't know for sure that this matter actually presents a problem, but as I said earlier, when we are talking about the health of ourselves and our loved ones, it would be foolish to take unnecessary risks. And this brings us to the next aspect of this particular disadvantage.
Availability.
Yes...I know. I already listed this as an advantage to using machine-shredded paper, and it is. But considering what we just talked about, those of us who wish to use the resulting compost on our gardens now have to see a certain disadvantage in acquiring material of this nature that is also safe to use. Well, I assure you, there is still plenty of machine-shredded paper around that contains no photocopied material, but a little more effort will be required to locate a suitable source. Because this material makes up such a large portion of the waste-stream, however, I personally think the added effort is well worth the time. This is also where the idea of having a community-based paper-shredder comes in handy, allowing you to make your own machine-shredded from the plentiful supply of unshredded waste paper that is still available everywhere. And in the instance of in-school vermicomposters,and similar situations, the chances are good that there is already a paper-shredder available, which means that simple sorting of the material that is to be shredded will solve the whole problem.
We have already dealt with the next three disadvantages in our discussion of newsprint and I trust you can find your way back to that section if you need a slight refreshing on the details. In short, these disadvantages are:
It Drys Rapidly, Leaks Light, and Can Become Compacted.
Like many vermiculturists, one of the main reasons I keep worms is to help in the reduction of waste materials that are destined for some already over-burgeoned landfill. If I have to exert a little more effort in obtaining a suitable source of this particular waste, I can take consolation in knowing that I am at least dealing with a material that truly makes up a large portion of the problem we face in this area.
Worm Bedding 6
Cardboard Part 1

Now we come to my favorite worm bedding, the one that in my humble opinion (I heard those snickers), is the ideal material available for this purpose. When I started my first worm-bin, I decided that cardboard would be my bedding material of choice, and if I had either kept my operation at the typical in-home size, or if I had had access to the necessary mechanical equipment required for producing large quantities of this substance (in its most suitable form), I'm sure I would still be using cardboard and nothing else. Unfortunately, shredding cardboard by hand (with razor knives and scissors) is a long and difficult process for anything but very small amounts, and unless the material can be reduced directly to particles the size of dust, degradation of the bedding can take a lengthy amount of time. This matter of slow degradation is not always a bad thing, mind you, just for the type of situation I was into at the time. Rather than go off on a tangent once again, however, I'll try and include as many explanations as possible of the pertinent aspects of cardboard usage inside the listings of advantages and disadvantages which follow.
Among the advantages of cardboard can be found the following items:
Availability and Consistency.
Cardboard is very likely one of the most available sources of worm bedding in the populated areas of the world, second only to the rest of the paper products in general, and to newsprint specifically. If we consider that Canadians produce more waste material per capita than any other country in the world (including our American friends to the south), and that one of our largest sources of waste is in the area of packaging, then we should be able to begin imagining just how many cardboard boxes this country goes through every day. According to figures that were supplied to me by Environment Canada (and mentioned elsewhere in this article), of the waste cardboard available in my home province in 1994, only 8.5% was being recycled. That means over 90% of the available material ended up at the local landfills, and even if we assume that the recycling rate has doubled since then (which I personally doubt), over 80% is still being buried. All a vermiculturist has to do is intercept the material before it gets hauled away, and of all the available substances, cardboard is one of the easiest to do that with. The simple fact of the matter is that of everything that makes up our waste stream, cardboard is the material most often separated from the rest, before it is thrown out, and for people who raise worms, that is excellent news.
Access to quantities of cardboard is made even easier by one very simple fact. For many people that have a lot of this material, it can be very expensive to dispose of. Consider how many grocery stores, small and large, occupy every neighborhood, in every city in North America. Once or twice a week (sometimes even more often), these stores receive their grocery orders. Approximately 80% of what they receive will be packed in cardboard boxes, which will be emptied, usually flattened out, then placed in large garbage bins to await hauling to the dump. In case you weren't aware of it, most companies that supply those large dumpsters, charge for each time that the bin is emptied. The rates may vary from one location to the next, but I can assure you, it is often costly enough that many store owners will be quite happy to have you remove a load or two for them, whenever you are able. Like always, talk to the individual merchant before removing anything from their property, and once you receive permission to do so, treat that merchant in a polite and conscientious manner. That way, you will not only obtain a good supply of great bedding, but you might even make a new friend.
One last point concerning this availability issue. Very often, the larger grocery (or department) stores in the various metropolitan areas will produce enough of this waste material that a recycling company will already be contracting to handle their waste for them. For that reason, --though it certainly can't hurt to check things out-- it may save you some time if you approach only the smaller corner-store type operations. Besides, if you are running anything short of a commercial operation, just one or two smaller locations will probably be sufficient to provide you with all the bedding material you require.
With all that said, there is very little to be added on the consistency side of the matter. Basically, cardboard is cardboard, and except for a few related issues which we will deal with further on, the simple fact of the matter is, if you start your worms in cardboard, and continue to use cardboard as their bedding material, there is very little chance that your worm population should have anything to complain about.
Environmental Friendliness.
Is it possible that some beddings are friendlier than others?
In a manner of speaking, yes. I realize that using any waste material for worm bedding, rather than sending it off to the landfill, is an environmentally-friendly act (which is why I haven't included it among the earlier lists of advantages), but using cardboard in this particular manner has at least one added benefit.
You see, even though there are many substances that can be diverted from the landfill for use as worm bedding, very few of those materials take up as much space at the landfill (in relation to their total weight) as cardboard does. Cardboard boxes, for instance, are not always flattened out before being disposed of, and crumpled cartons tend to use up a lot of unnecessary space. If the boxes are flattened out prior to burial, they can still present another problem. Under tremendous pressure, and protected from the elements by a multiple layering effect, this cardboard can take an awful long time to decompose, thus causing the landfill to reach its capacity much faster than it normally would, if used only for rapidly-decaying materials. So you see, if we use 50 pounds of cardboard for worm bedding, as opposed to 50 pounds of green waste (for example), we save a lot more in the sense of available disposal space, and that is what I mean by a greater degree of environmental friendliness.
A Good Feed Source.
In most cases, a good feed source does NOT equal a good bedding material. The reason for this is that most feeds are too high in protein to double as a bedding substance. The worms (who by their very nature eat constantly) will soon burn out in a high-protein bedding, and when I say burn out, I mean that almost literally. The constant intake of protein will raise the internal temperature of the worm, which results in a binful of wigglers that are no longer wiggling. They will also not be eating, mating, or moving, since they will all be dead. What they will be doing, is laying around in the bed, racing each other to see who can rot first. I'm sure there is a very nifty scientific explanation for this phenomena, but I can only attest to it as the result of having killed several batches of worms in this manner. When someone was good enough to offer an explanation of the problem to me, I chose to accept it.
What this means of course, is that with many substances --such as newsprint or machine-shredded paper--, a feed source apart from the bedding material is required for happy, healthy worms. There are exceptions to this rule, however, and cardboard is one of the most notable among them. Not only can cardboard serve as an excellent bedding material, but if you are so inclined, you can have it pull double-duty, serving also as the only feed source in the bin. It has even been said by various worm experts that worms raised strictly in cardboard will be larger, healthier, and more prolific (sex-crazed ) than worms raised in any other material. There are a few explanations for these opinions, and also one or two qualifications which should be kept in mind.
First of all, why should cardboard make a good feed? Because of the cellulose (a complex carbohydrate derived from plant fibre) it contains, as well as the glue (usually made from animal by-products) that is used to bind the various layers together. In combination, these substances provide the worm with just about everything it requires to grow up big and healthy. If there is anything lacking in this particular bedding/feed, it is the additional protein necessary for giving the worm a firm, resilient body, something desirable to anyone raising worms as fishing bait, even though the worm itself may consider it to be an optional trait. (This deficiency is easily rectified by a weekly supplement of commercial feed.)
The main qualification that must be taken into account is the condition of the cardboard in relation to its availability as feed. When pulverized, this material is pretty much ready for instant ingestion by the worms, and conversion of the bedding into castings can be expected to occur in as little as 6-8 weeks. This is, of course, assuming the presence of an average worm population, which for the sake of argument can be approximated at 2 pounds of worms per cubic foot of bedding. If, on the other hand, the cardboard is not pulverized, but simply shredded or crumpled, it will take a considerably longer time before decomposition progresses to the point where the worms can use the bedding material as feed. In that situation, a secondary food source will be required until such time as the cardboard reaches a suitable state. (Continued next article.)
Worm Bedding 7
Cardboard Part 2
I mentioned elsewhere in this lens the fact that peat moss, bog soil, or shredded paper could all be used to fluff up other bedding materials that were too dense, or heavy. Not only is the same thing true of cardboard, but of all the materials used in worm bins, none produce (in my opinion) a nicer final product than this one. When pulverized prior to use, cardboard is already light and fluffy, and even if used in a rougher state (shredded or crumpled), it will eventually result in an extremely friable compost. In fact, cardboard may be the only paper-based bedding material that doesn't present the home-based vermiculturist with compaction problems.
Usually Has No Odor.
Another of those wonderful materials that has no inherent odor unless it is left lying around in very large quantities, or in a dampened condition. (Once installed in a worm bin, even moist cardboard is usually odor-free, and if it isn't, the bin conditions should be checked.)
Among the disadvantages of cardboard are the several smaller problems which relate to this one main point:
Cost or Effort.
Considering everything I have already said about the availability of waste cardboard, you may be wondering why this matter of cost should be the disadvantage I mention, and you might even be wondering exactly what cost I am referring to. Well give me a moment and I'll explain.
First, it must be understood, cost is not always determined by an actual expenditure of cash. Time is also a valuable commodity, as is work, and unless you happen to be in a very fortunate situation, the conversion of raw cardboard boxes into suitable worm bedding can involve a considerable outlay of both. You see, the waste material is definitely available, but simply crushing the boxes and wetting them down is a very crude technique that is seldom satisfactory in the long run. This means you must either pulverize the cardboard, or at the very least, reduce it in size quite drastically.
There are two, possibly three main problems encountered when the boxes are merely crushed and moistened as a means of preparation.
First of all, unless you are using a relatively large bin-system, you will have to find very small cardboard boxes to crush, or you simply won't have enough available space in the container. (If later on, you should try to use the same method to add fresh bedding to the system, you may also find yourself squishing a fair portion of the existing worm population.)
Next comes the problem of harvesting those little wigglers from within such a system. You see, until the cardboard becomes decayed enough for the worms to ingest, they will feast themselves on the glue that is available between the layers of paper. They will accomplish this by squirming inside those various layers via the corrugations, and that is where you will have to find the little critters when you need them. Aside from having to peel the paper layers apart from one another, when you do locate the worms, they will be covered in the very slippery glue substance, making them almost impossible to pick up. (If you have no intention of harvesting the worms until all the bedding is converted, this particular point should not prove to be a problem.)
Finally, if you decide to supplement the cardboard with an additional feed source (kitchen waste, compost, etc.), you will rapidly discover the difficulties involved in "burying" anything in crumpled cardboard.
What this means, of course, is that for most practical uses, you will find that cardboard bedding works best when reduced to pieces of approximately 1 square inch or smaller, with pulverization working best of all. If you have read any of the earlier articles I have written on this subject, you may recall that I acquired the square pieces of cardboard bedding for my initial worm beds by cutting boxes into long strips with a razor knife, then cutting the strips down with heavy-duty scissors. (I eventually cut 145 pounds of one-inch cardboard squares over a period of roughly 45 days, and sometimes late at night, when the moon is full, I can still feel the resulting cuts and blisters which I acquired along with the bedding material. ) So if you figure the hours involved in this process, and assume even a minimum wage for my efforts, you can see the cost I am referring to.
Now, as I've already said, pulverization works the best, but unless you happen to own a hammer mill, or at least have access to one, you are not likely to encounter a great amount of cardboard in the form of dust (other than the unsafe material prepared as insulation.) The idea of purchasing a hammer mill specifically for "bedding preparation" is more than a little silly considering the cost, and even renting the use of this type of equipment from time to time can get expensive. (If you should obtain the use of such a piece of equipment, remember to wear a face mask to prevent the accidental inhalation of the airborne particles.)
So in the end, though I consider waste cardboard to be the finest bedding substance available for indoor worm composters, the problems involved in obtaining it in a suitable form, or the effort required to convert the raw material to the necessary condition by hand, makes this substance suitable only for the smallest of operations. That is, unless you happen to be one of the fortunate few who just happen to find yourself in a very rare situation. In that case, congratulations, you lead a truly blessed life.