Worm composting is a very rewarding endeavor, but can also be a little challenging to get right at first and if you get something as important as worm bedding wrong, then you’ve made it harder on yourself from the start.
To successfully raise worms you need high-quality bedding. There’s no two ways about it..and we’re here to help.
The effectiveness of your worm farm or worm composting bin, the growth of your worms and output of worm castings is directly related to the quality of your bedding.
- Use soft, absorbent materials that hold moisture but also provide good aeration, oxygen flow and allow for easy worm movement
- Keep bedding pH neutral at 7 or slightly acidic (no lower than 6)
- No sharp materials
- No materials potentially containing toxic chemicals (like colored magazine paper)
- The perfect worm bed: Gentle organic materials, adequate moisture (damp but not wet), oxygen flow, pH neutral, carbon to nitrogen ratio of around 30:1
It’s your compost worms’ house, their living area – so, it’s safe to say bedding is one of the most important aspects of worm composting and needs attention to detail.
If you’ve been looking for answers to questions like, “which bedding is safe?” or “what type of materials should I use for my bedding?”, you’re on the right page.
Let’s get into more detail and give you all the information you need to create a conducive habitat for your worms to thrive in.
What Characteristics Make The Best Bedding Materials For Worms?
Due to the sensitive nature of worms and the fact that they spend all their lives in your worm bins’ bedding reproducing, growing, and eating (their diet is also composed of the bedding), it is very important to pay close attention to what you make your bedding with.
Get this part right, and you can say hello to some high quality worm castings on a regular basis!
The best bedding materials for worms should have the following characteristics:
A good bedding material for worms should have the ability to retain moisture since worms need moisture to thrive and be healthy.
So, when choosing bedding materials for worms make sure that you go for something that is highly absorbent and has the ability to hold on to moisture.
You don’t want soaking wet, but you do want a consistency like a damp sponge.
Although earthworms can survive with relatively low oxygen and carbon dioxide levels, they still need oxygen to survive.
Any material you intend to use for your bedding must allow the flow of air.
Even though worms need moisture for growth and survival (this is how worms breathe), their bedding shouldn’t be soaking wet.
Soggy, overly wet bedding may deplete oxygen levels, a condition in which anaerobic bacteria can produce toxic substances that can hurt the worms at best.
At worst, your worms can suffocate and die.
TIP: Some vermicomposters drill tiny air holes at the bottom of their worm bin to allow excess water to fall through.
But be sure to add something like a tight mesh so that your worms don’t escape.
You may even attach a tap and drain it regularly to make use of worm tea and leachate.
Bedding has to be added regularly, and even in greater quantities than food scraps, so you need a bedding material that you have easy access to.
Worms are very sensitive, meaning the acidity-alkalinity level must be perfect to ensure they thrive.
Maintaining a pH or around 7.0 is a great way to ensure they are healthy.
Between 6-7 works. Some worms can even handle a pH of 8 but this is pushing your luck.
You can regularly keep track of the pH by using litmus paper or a pH kit.
Chemical-Free and Non-Toxic
Worms have very sensitive skin, this means the materials that will be introduced to their bedding must be free of chemicals and toxins that can be harmful to the worms.
Carbon is a vital component of life on earth.
The habitat you create for your worms is going to be composed of organisms that rely on carbon-based inorganic matter for food.
So, the bedding material you choose for your worms should be carbon-based as carbon is very vital for all the processes that occur in the worm breeding and composting process.
You want to keep your carbon to nitrogen ratio around 30:1 – the carbon can move up or down a few spots from 30, but that’s around the sweet spot you want.
What Should I Use For Worm Bedding?
When choosing materials for worm bedding, keep in mind the sensitive nature of worms and how materials with chemicals and toxins may harm them or even cause death.
While worms are good at filtering toxins, some worm bin bedding materials you’re considering may be too much, even for their toxin filtering system.
The following materials are what will work well and what won’t for a worm bedding material – we’ll explain in greater detail why they work and don’t below this table:
|WORM BED MATERIALS TO USE||DON’T USE|
|Shredded Cardboard (brown)||Grass Clippings|
|Shredded Newspaper||Wood Chips|
|Compost (not fresh, leave to cool)||Sharp Materials|
|Straw||Fresh/Wet Coffee Grounds|
|Aged Manure (horse, chicken, cow etc)||Highly Acidic or Alkaline Materials|
|Peat moss||Non-Absorbent Materials|
|Coco Coir||Materials That Stick Together|
|Dry Leaves||Colored/Bleached Paper (like office paper)|
|Garden Soil (with some small grit)|
Shredded Cardboard (brown)
Brown cardboard, when shredded, works effectively as a bedding material for worms because it allows aeration (it has air pockets) and it is also very absorbent.
It fulfills the two major characteristics of a good bedding material: absorbent and providing aeration.
Shredded newspaper also works well, but make sure to use only the pages without thick color as the colors may contain toxins that can be harmful to the worms.
If you’re not sure of the ink used in printing the newspaper, you can soak it in gray water or day-old water.
Wait a couple of hours and all the chemicals will diffuse out, you can then pour out the water and squeeze out what remains.
Aged compost works effectively as worm bedding material.
Be sure it’s not totally fresh as the heat emitted can lead to a hot worm bin inside and go above ideal temperatures for your worms environment.
You can mix in other bedding materials on this list, as well as food scraps and you’re good to go.
Straw, Hay or Dried Yard Waste
Due to the structure of straw, it has a lot of space that allows for aeration, so it will work well as bedding material for your worms.
Aged Horse Manure (Chicken or Cow Manure is also fine)
Aged manure, especially horse poop, is a great choice for worm bedding.
A study(1) also found that horse manure comprised of the perfect 30:1 C:N ratio as seen in the image below:
It is great because it effectively serves two purposes; it is a great bedding material and also provides a good food source for composting worms.
The only downside is how heavy it is, making it hard to transport.
It might also contain deworming medication used for the horses, but long exposure to sunlight can break down the medication and may make the horse manure safe.
NOTE: It’s important for it to be aged since fresh manure can be hot and cause overheating
What NOT To Use For Your Worm Bedding Mix
There are some materials that shouldn’t be found in a worm bin.
These materials can create an environment that is not conducive for the healthy growth of your worms.
Make sure to leave these items out when constructing your worm bin.
While grass clippings may seem like the perfect organic matter to add to a worms diet and bed, in a closed vermicomposting system, you may find that it heats up the bedding to levels that can put your worms in danger.
A minimal amount may be fine, but generally avoid fresh grass clippings in your worm bed.
Wood chips and wood shavings are another material that seems like perfect bedding but doesn’t really work that well for what we’re trying to do.
They have a really high C:N ratio (600:1), don’t degrade very well, could have abrasive edges and don’t hold moisture that well either.
These are all traits that don’t make for ideal worm bed material.
The only time you’d use them is if you’re worried about really high nitrogen levels in your worm bin.
You shouldn’t use sharp materials for two reasons.
1) They may hurt the delicate skin of worms by cutting them
2) Typically, sharp or abrasive things are made from materials will break down slowly, if at all – for example, jagged stones, sharp pips and plastics.
If you’re going to use something beneficial like egg shells, then be sure to grind them down into a fine grit (this also helps your worms digest organic material in their gizzard).
If you’re going to use any plant material in your worm bedding, make sure it’s the soft part and not the thorny and sharp parts.
Also watch out for stuff like freshly chipped wood and thistle weeds.
Fresh Coffee Grounds
This also has to do with pH levels.
While dry, used coffee grounds themselves are alkaline and a good addition to a worm bin, the coffee drink itself is highly acidic.
Store your excess coffee grounds for a while, so that they dry out and then they’re fine to use in your worm bins and as worm food.
If wet grounds containing the coffee is used in excess, this could potentially raise the acidity of your worm farm.
The best way to use coffee grounds is if they’ve been left to dry and become neutralized, then it can be used in moderate amounts.
Highly Acidic or Alkaline Materials
The pH of worm bedding should be kept as neutral as possible – between 6 and 7 on the pH scale is perfect for most composting worms like red wigglers and European or African night crawlers.
Nothing extreme on either side of that pH scale should be happening.
If it is, this means the materials used are causing the vermicomposting process and environment in your worm farms or worm compost bins to be too acidic or too alkaline.
This can negatively affect the health of the worms and cause poor growth and reproduction, cause the worms to try and escape or worse, death.
Worms need a moist environment to grow and reproduce.
Bedding material must be absorbent enough to hold moisture to create a moist, not soggy, habitat for the worms, like shredded paper.
And since the worms also eat their bedding, nothing inorganic or hard should be introduced to the worm bedding.
Organic and absorbent material that will create a moist environment is what’s ideal for the rearing and development of healthy worms.
Materials That Stick Together
Two things are very important when making worm bedding; aeration and drainage.
Worm bedding material must be light, fluffy, and allow the flow of air.
Materials that are too packed together prevent the flow of oxygen and also trap moisture, leading to sogginess.
Worm Bin Bedding – How To Put It All Into Your Worm Bin
Now that you understand the materials that are great for worm bedding and what not to add to your worm bin, it’s time to put it all together and create your worm bin.
It doesn’t have to be the exact materials we use below, but it’s best practice to exchange for something similar in exchange.
You can follow our steps below to put everything together:
- Step 1: Add your rehydrated coconut coir
- Step 2: Add your shredded paper
- Step 3: Add some “grit” like potting soil or your standard yard soil
- Step 4: Add a damp worm blanket. Whole newspaper pages work.
And you’re done! The time for adding worms has come.
Below are also the tasks you need to do before you can perform the easy step by step guide above:
With an understanding of what to use and what not to use, sort through the available materials you have and pick out what you’ll use to make your worm bin.
When sorting paper, make sure to exclude very colorful pages and other things like tape, glue, or plastic windows on envelopes.
After sorting and picking your materials, you have to shred anything that needs it into smaller bits so they can be easily combined with other materials.
Papers and cardboards like egg cartons need to be shredded to small pieces.
Soaking up your worm bedding materials (especially paper) is a great way to remove chemicals and other substances that might be harmful to your worms and also add moisture to your materials.
Strain and Squeeze
After letting your worm bedding materials soak, if you notice it is too wet, strain out the water and squeeze to get rid of excess moisture.
You want your bedding materials to be damp, not soggy.
Too much water is not good for your worms.
You can keep it most by using a spray bottle to spritz it with water at regular intervals depending on the humidity and temperature in your location.
An effective worm bin is one in which there is adequate aeration, so it’s important to make sure your worm bedding materials are not sticking together and preventing airflow.
After fluffing and making sure there is enough room for aeration, spread everything evenly in your worm bin.
You’ve just created an enabling and healthy environment that worms love.
Worm Bed Materials FAQs
These are some questions we most commonly get asked in relation to making the perfect worm bed and the common issues vermicomposters come across:
How to Fix the pH of Worm Bin Bedding
If you’re worried that your worm bin bedding is going outside of the ideal pH range of 6-7, there are a few things you can do:
Too Alkaline (above 7, approaching pH8)
Peat moss veers towards the acidic side of the pH scale and just adding some to the top of your overly alkaline soil can slowly filter down to bring your soils pH level down to more acceptable levels.
Keep testing the soil over the weeks and months to ensure it is having the desired effect.
Too Acidic (below pH6 or approaching it)
Generally anything that will cause an imbalance should be avoided but in this case, wood ash can increase pH and make the acidic enviroment where your worms live more alkaline and hospitable.
Sprinkle a small amount on the top soil and come back in a few days to monitor the pH levels.
It could take a while to take effect, sometimes months, so don’t go overboard as you could go to the opposite extreme.
How Often Should I Add New Bedding to My Worm Bin?
You should add new bedding every time you add food waste or kitchen waste into your worm bin.
This will ensure there is adequate bedding for the amount of food going into your bin and will keep the carbon nitrogen ratio close to that sweet spot of 30:1.
How Often Should You Change Worm Bedding?
It’s recommended to change the bedding every 6 to 9 months but this will depend on the size of your bin and what your worm population is relative to the size of your worm farm or bin.
Oftentimes, you may not even need to change it as you’ll be constantly adding to it until it’s time to harvest your worm castings.
At which point, you just make a new worm bed.
Can I Use Sawdust for Worm Bedding?
It’s not advisable to use sawdust or wood chips for worm bedding.
Mainly because they might have been treated with insecticides, contain pesticide residue and have chemicals that can be harmful to worms.
Can I Use Colored Newspapers and Magazines for Worm Bedding?
The type of color used in the printing of the paper is what might make colored newspapers bad for worm bedding.
The colored print might contain chemicals or heavy metals that can be harmful to worms.
You can only use colored newspapers if you know the type of color used and you’re sure it doesn’t have harmful chemicals.
But generally, it’s safest to stay away from colored paper.
Can I Use Office Paper for Worm Bedding?
Bleached white office paper contains chlorine which is used in the bleaching process to turn the paper from brown to white.
Chlorine can cause damage to the skin of worms, so you should be careful when using white office paper.
If you have nothing else available, you can get try to rid of the chemicals by soaking the paper in water for a few hours.
Summary and Final Words
A good worm bed is essential to making sure that your worms – whether you’re using red worms, night crawlers or any other composting worm – are happy and that the finished compost and castings are of high quality.
The better your bedding, the more worms will be happy and the happier you’ll be with what they give you in return! We hope our post has given you everything you need to create a comfy bed and environment for your wiggly friends.
(1) Kristiana, Ris et al. “Monitoring of the process of composting of kitchen waste in an institutional scale worm farm.” Water science and technology : a journal of the International Association on Water Pollution Research 51 10 (2005): 171-7 .