Worm bins are easily one of the best additions anyone can make towards achieving a zero waste kitchen. Worm bins serve as an easy to maintain location to dispose of any leftover food scraps from cooking. You can add almost any organic material into a worm bin, but there are many out there who question whether it is OK to add sawdust in there as well.

Sawdust can be added to a worm bin, but you need to do it in moderation.  When adding to a worm bin, add equal parts food scraps and moistened sawdust.  Adding too much sawdust will sap the moisture from a worm bin and make the contents difficult to break down.  

Problem is, not all sawdust is created equal.  There are things you’ll want to avoid.  And if you don’t have sawdust, what else can and can’t you put in a worm bin?  What bedding is best for a worm bin? What worm bin is the best to use?

These are things that every first-time owner of a worm bin will find themselves asking, sometimes even veteran owners may learn something new.

These are the do’s, the don’ts, and tricks of owning a successful worm bin.

Related: If you do not already have a worm bin, my recommendation is the Worm Factory 360 from Amazon. It is really easy to use and fits nicely into any unused corner on the lanai or even in the kitchen!

Using Sawdust in a Worm Bin

When feeding worms in a worm bin, you’ll want to include two things, what I like to call greens and browns.  Greens are pretty much any food scraps leftover from cooking.  Fresh food that hasn’t dried out yet.  Browns are dried cellulose based materials such as shredded paper, Coco coir, dried leaves or sawdust.

When adding greens and browns, you will want to be sure that the browns have been moistened to the point where a drop of water can be squeezed out.  You do not want it to be too wet, nor too dry.

Sawdust does a really great job of sucking moisture out of its environment.  If your bin is out of balance and you notice a high moisture content, adding dry sawdust can help get things back into balance.  Majority of the time though, you will want to pre moisten sawdust.

Now the only problem with sawdust is where it came from.  Most wood products these days are treated.  Feeding this treated sawdust to your worms can have harmful effects.  Be sure to try and source your wood from hardwood cabinet makers or wood turners as the sawdust will less likely be contaminated.

What You Can’t Put in a Worm Bin

The obvious answer will always be anything synthetic, seeing as worm bins rely entirely on the process of composting to be successful.  Anything like plastics or metals will not be consumed by the worms. 

Even with some organic things there are limits, especially if you have too much of one thing in your diet.

Which means that you need to know when to add certain things, when to leave some things to decompose naturally for a bit and when to move some parts of a worm bin out.

  • Animal products: While the worms will love most natural products, things like bones, fats, skins or even hair is not something they can eat.

    This means that adding these to your worm bins will only cause immovable parts of untouchable goo that you will have to empty by hand to get completely removed. A Black Soldier Fly Worm bin can handle these things.

  • Fabric Tea Bags: While you can certainly add normal tea bags that are paper, throwing anything with fabric into the worm bin will be ignored by the worms. This counts for more than just tea bags.  Strings, cloths, or even small pieces of fibres will not be processed by the worms.

  • Dry Things: While the worms will eat almost anything, dry products like stems or sawdust will take a significantly longer time to be decomposed.

    The worms must work extra hard to break them down or the moisture levels of the worm bin become unbalanced.  Moisten these items before adding to the bin.

  • Labels: Something that you should always look out for as well are the labels printed on a lot of produce, these are usually stickers with residues on them. These stickers can never be consumed by the worms and removing them before placing any produce in a worm bin will mean a lot less headaches in the future.

  • Citrus Peels: Worms hate orange and lemon peels.  While it won’t harm your worm bin, they will not get broken down.  When it comes time to empty your worm bin you will be sifting citrus peels out by hand.

Related: Worm Composting: Hawai’i’s Answer to Fertility in the Garden

What Can You Use in Worm Bins?

For all the things that you cannot put in worm bins there is a long list of things that worm bins can easily process. This will mean a lot less smelly trash bags and a lot more worms willing to convert your food trash into compost that you can then use to make more food.

  • Fruits and vegetables: This is the obvious answer, but it is also the best one. Throwing in any scraps or just older food will create the perfect worm colony, ready to eat. These are the things worms would eat naturally in the wild. 

    By letting them get the best mix while in your worm bin, you will be rewarded with some of the best soil possible for planting fruits and vegetables.
  • Breads: The best thing about old bread is that it can be used as a rock.  However, after you’ve used stale loaves to crack the nearest walnut you can simply throw them into your worm bin.

    You should let the bread soak up some water before adding. This softens the bread and will mean that the worms can almost instantly start eating.
  • Tea and Coffee: Just like humans across the world, worms are in love with the taste of coffee and tea, but maybe not in the same way we are. Because these two substances are entirely organic, worm bins can easily and effectively get rid of the waste created by consuming our favourite drinks. 

    You no longer need to worry about the waste that a nice hot cup in the morning creates.

How much bedding should go in a worm bin?

The amount of bedding required for your worm bin will vary greatly depending the size of the bin you are using. Some people prefer to get a bedding of at least one inch thick before adding any soil or organics to be composted.

This means that the worm bin will need a very equal covering of the materials you have chosen, preferably a mixture of either sawdust or shredded paper and soil. Once you have placed the bedding you will need to ensure that it is entirely moist and ready to be pushed flat across the surface of the bin.

The true measure of whether you have enough bedding in your worm bin will be the behaviour of your worms. If they are constantly agitated and trying to escape it may mean that your bedding is not enough or moist enough, simply adding more and making sure it is moist enough will ensure the happiness of the worms.

The best worm bins

As a frugal homesteader, I like to try and make things out of what I already have on hand or can find for free locally. 

I have made worm bins out of old bathtubs, 5 gallon buckets, plastic bins, trash cans, you name it.  I have found each system to work just as well as any commercially purchased worm farm, which I have tried as well.

If you are looking to buy a worm compost bin, there are two that I have found to work really well.  They are easy to manage and do a great job at separating finished compost from areas of the bin where the worms are actively feeding.

My favorite commercial worm bin is the Worm Factory 360. I used this worm bin while working with the Permaculture Skills Center in Sebastopol, CA, an educational facility focused on all things regenerative.  

This worm bin was able to handle food waste from dozens of employees and visitors alike while also making it really easy to harvest finished compost and “worm tea.”

Another design I really liked was The Worm Tower.  The idea is that the finished compost falls to the bottom funnel, while the active area is in the upper, wider half of the bin. 

This worm bin is even easier to harvest finished compost from than the Worm Factory and has less parts to clean, but I have found that I flush out more compost worms than I care to when I try harvesting the compost.  Still a great product though.


Adding the right amount of sawdust to your worm bin will mean the worms can easily process the waste saw dust that you may have. This will give you a lot more compost that you can later use to grow your very own vegetable garden that looks as good as any other.

Getting the balance right and keeping it that way in your worm bin really is a simple process of choosing carefully what you’re adding and not adding too much at any given time.

Now that you know how to manage a bin, it’s time for you to get out there and raise some worms of your own.  Your garden will love you for it.

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