Ultimate Beginner's Guide to Worm Composting

You’ve decided to start a worm farm! A unique but rewarding journey awaits you. 

It is time to prepare yourself for the viral question that your loved ones may ask;

"Would you still love me if I was a worm?" 

After you read this guide you will easily be able to reassure anyone who asks you that question that you would be able to see to all of their worm wants and needs and provide them with a life of worm dream's.

 

Jokes aside, let's get into it!

 

Temperature

The ideal temperature is around 77 degrees Fahrenheit. This is the most efficient temperature for food consumption rate as well as reproduction rates. However, Red Wigglers will do well anywhere between 60-80 degrees. As you depart from that temperature range, they may begin to become more sluggish and eventually die around temperatures below 35 degrees, or above 90 or so.

 

Note that this is the internal temperature in their bin or environment, which can be warmer or cooler than ambient temperature. Use shade in the summer, or thick insulation (like straw) in the winter to mitigate extreme temperatures if necessary. If worms are exposed to lethal temperatures, any cocoons that they may have laid will remain dormant and hatch when temperatures return to more favorable conditions, so even if your bin freezes you will have some worms survive for spring!

 

 

Oxygen and Water

How long can you hold your breath?

How long can you go without drinking water?

How long can you not eat any food?

Worms have the same hierarchy of needs. They will die very quickly if they cannot breathe, but, if they have water, they can go months without food.

I've included air and water together, because in a worm bin air and water have a directly converse relationship.

More water means less air, and more air means less water.

Your worms (and the necessary beneficial microorganisms) need access to enough water to be hydrated, but also enough air to breathe.

 

Lets talk about sponges.

 

Imagine a sponge. If you can actually grab one physically, it will help you understand this concept.

A sponge has a certain amount of space within it that can absorb and hold water. If those spaces are not occupied by water, it is occupied by air.

Think of a (or physically do this right now) totally saturated, sopping wet sponge. It is holding as much water as it possible can, or, in other words, it is at 100% moisture. 

Now (mentally of physically) give that sponge a squeeze. A stream of water should leave the sponge, and as you let go of the squished sponge, it goes back to its normal size, absorbing the air around it as it does so.

The sponge is now likely at about 50% moisture - half of its available pore space is occupied by water, the other half by oxygen rich air.

You want your worm bin to be like this wrung out sponge. If a worm were inside the sponge somehow, it would have sufficient access to hydration without jeopardizing its access to oxygen.

Worms will survive down to about 30% moisture, or as high as 90%, but you should aim for around 60-80%. 

You can estimate the moisture level of your bin by taking some of the material out and giving it the "sponge treatment." It might take some time, but you'll get the feel for it. 100% moisture is obvious - it will be very waterlogged. 0% moisture is obvious too - it will be bone dry. Mentally imagine how it would feel if it were 60-70% of the way to saturated and dry or wet your bin if necessary (continue reading to learn how to dry your bin).

Other signs that your bin is at a good moisture level include:

1. An earthy, forest-like smell.
2. A lack of pests like flies and gnats
3. A fluffy, spongy, or crumbly feel, like a healthy soil
4. Happy, healthy worms

Signs that the bin are too wet are the opposite.

 

Managing Moisture

More often than not, you won't need to worry about adding water to your bin. Keeping the bin drier is usually the obstacle.

As you feed the worms you will often be adding water at the same time. Fruit waste, such as banana peels or watermelon rinds have a lot of water in them that they will release as they decompose.

If no efforts are taken to offset that water, the bin will likely become too wet eventually.

Drying the bin is as simple as mixing dry bedding material throughout the bin where it needs to be drier. The dry bedding will absorb the excess moisture and help get your bin to the correct levels.

 

 

Water Leaking from the Bottom of the Bin

Contrary to misinformation online, not only should your worm bin not be leaking water from the bottom of the bin, that liquid is not recommended for use on plants.

From the Manufacturer's Instructions on the Worm Factory:

The liquid runoff that settles in or below the vermicompost or worm castings is known as leachate. Leachate can contain phytotoxins (toxins that can harm plants and humans)... Some leachate can contain harmful pathogens because it has not been processed through the worms intestinal tract. It should not be used on edible garden plants.

If water is leaking from the bottom it is too wet and you need to mix dry bedding into the bin to take care of it.

 

 

Food

There are 2 classifications of organic matter (food) in a worm composting context; Bedding and Food.

 

Bedding is the "sponge" structure of the worm bin - it holds water to keep the worms hydrated, but also leaves space open for oxygen exchange.

In the classic composting world, these are your "brown" materials.

Examples of Worm Bedding Include:

1. Shredded Cardboard

2. Shredded Paper

3. Fall leaves

4. Coconut Coir

5. Straw

6. Finished Compost

7. Aged Manure

8. Saw Dust

9. Finished Worm Castings or Vermicompost

 

 

Food / Greens

Organic Matter that is higher in nitrogen, and typically has a higher moisture content, like fruit and vegetable waste, coffee grounds, etc., is considered food.

These are the primary source of nutrients for your worms and castings, and processing this waste is the main reason people get into worm farming.

 

Please note you cannot run a worm bin on these food scraps alone. They do not provide any "sponge" structure to your worm bin necessary for them to breathe. Upon decomposition, they release a lot of water and your bin can get waterlogged quickly.

Besides that, these foods are high in nitrogen, which means if you add too much they can begin to hot compost - causing your bin to heat up more than what they worms can survive.

So try to make sure you are never adding so much food that it is causing your bin to become too wet or start to hot compost.

Here is an infographic from the squirm firm that gives a good outline of worm-edible foods. 

 

 

 

Setting up the Bin for the First Time

 

When you start, you should have at least one square foot per pound of worms, with at least 3-4 inches depth of bedding.

Your bin will start as 100% bedding.

Over time as you add food you may notice that your bin is starting to get wet from the water rich food, or is becoming somewhat anaerobic for any other reason. This is when you will want to add more bedding.

Bedding is a fix-all for worm bins. Use it as much as you want, and whenever you come across almost any problem in the bin it will be solved by adding bedding.

So start with 100% bedding, and then add as needed to keep your bin aerobic.

 

How to Make and Use Bedding

1. Identify which bedding materials are locally available, and free to you.

2. Be aware of the strengths and weaknesses of those beddings (some will clump together and restrict airflow, others don't hold moisture very well etc.)

3. Create a mix of beddings that will compliment each other and create a nice spongey feel bedding.

4. Get them to an appropriate moisture level - only a couple of drops of water should come out when you squeeze it. I typically do this by soaking it in a bucket of water and then squeezing out the excess.

5. Add it to the bin!

Remember that bedding needs to be high in carbon and allow for airflow while maintaining appropriate moisture levels. Individual bedding materials may not be sufficient on their own, and will need to be mixed with others. Your bedding mix should hold water while still allowing for air like a sponge.

 

 

What Do I Need to Know About Feeding My Worms?

There are many different kinds of foods you can give to your worms - Each kind can have its own caveats. Here are my top guidelines to be aware of while feeding your worms.

 

Ask your worms what they can eat - Don't add throughout the entire bin

Until you are familiar with the type of food you are adding and how the worms/bin will respond, don't add the food throughout the entirety of the bin. This allows the worms, if they don't like the material/conditions you've created, to just go to a different section of the bin (whether horizontally or vertically). If it has been added throughout the entire bin and something has gone wrong, their only option is to escape the bin as a whole. It is a good idea while you are still learning to always leave a portion (a third or so) of the bin free of any actively decomposing food as a safe space for the worms if you make a mistake elsewhere in the bin.

This also allows you to figure out if a food/type of organic matter will be okay for your worms. You can ask your worms directly by adding some of the food in a small area in the bin. If they don't like it, worst case scenario is that they'll avoid that area and not touch the food. If they swarm it right away, they like it.

 

 

Aerobic Conditions and Bedding

You need to make sure your bin stays aerobic. Organic matter that will contribute to aerobic conditions in any quantity is considered bedding. Other organic matter would be considered food. The majority of your bin should be bedding, or finished worm castings/compost, at any given time. This is important.

Avoid certain types of foods

Generally you'll want to pass on feeding citrus, meat, dairy, spicy foods, salty, greasy, or oily foods. The worms can and will eat these foods, but it may take a longer time for them to do so, and other undesirable organisms might take advantage of the available food in the mean time. 

Bury the food

By covering food with a small amount of bedding (1/2 inch to 1 inch), worms will be protected from any light coming into the bin that would scare them away from the food, the food won't dry out, and it will help hide the food from bugs such as fruit flies.

Fruit and Vegetable Skin

Although you don't need to do this, the worms will be able to eat a watermelon/grape/apple/any fruit with skin much faster if the skin has been punctured or they are able to access the "flesh" inside.

Man, that sounds morbid without context. But, when I feed my worms zucchini, for example, I don't just put it in whole. You'll want to expose the inside somehow. Breaking or cutting it in half, cracking it open, or cutting a chunk out of it will greatly decrease the time it takes the worms to eat all of it.

Microbial Populations

The more microbes and more microbial diversity, the better. The microbial population should establish itself after the first few weeks (and is really only a concern as you first start), but you can always improve it/add to it by adding little inoculums of healthy (KEY WORD) soil/organic matter from healthy soils. I often go to parks, forested areas, or healthy garden soils. Just take a small amount of material (half a cup) and toss it in the worm bin. Be aware that you're adding anything else that might be in that handful - like any bugs. This usually isn't a problem because if you're not fostering an environment where bugs will thrive then they will go away, but you might introduce some roly-polys, or springtails, or millipedes that will live alongside your worms in small, normal amounts if your worm bin isn't totally unmanaged.

How much food to add at once - Overfeeding

There are a few things that limit how much food to add at once. You don't want to create anaerobic conditions from excess water, you don't want to start thermophilic (hot) composting, and you don't want to add so much food that the worms can't eat quick enough so other organisms start flourishing on the extra available food. Whenever you make one of these mistakes you can always remove the food you added to help resolve it, and if you are following the practice of only adding food in certain areas of the bin then its an easy fix. Read on to learn more about all of this.

Overfeeding and Excess Moisture

As you are adding water-rich foods, like fruit/vegetable waste, they will release their water into your bin as they decompose. If too much water is released it can waterlog the bin and create anaerobic conditions. You will eventually need to add more dry bedding to counteract the excess moisture if the bin starts to get too wet.

Overfeeding and Pests

Ideally worms will be the main macro-organism eating your food. However, if some food waste hasn't been eaten by the worms and there's plenty of excess food that other organisms don't have to try to outcompete the worms to eat, you may start to see mites, mold, or other unsightly (but usually not inherently bad) organisms start to feed on the material. The key is to just provide enough for the worms - as long as you make sure its worm-edible, nothing is going to be able to outcompete the worms. Burying the food of course will help with this.

Overfeeding and Thermophilic Composting

If you add too much food that is too high in nitrogen the rapid microbial growth can cause the material to heat up - which can kill your worms. Be aware of the general Carbon to Nitrogen ratio of the food you're adding. The higher the nitrogen content, the less of it can create heat. In situations where you are feeding them higher nitrogen material (such as coffee grounds with a 20:1), if you add it in small concentrations (only a small amount at a time/spread out more thinly) it will help prevent the heating up effect. Materials like fruit and vegetable waste are usually around 35-40:1 carbon to nitrogen and aren't so prone to heating up unless you have added a lot. If you are following the first step of not adding food throughout the entire bin the negative effects of this will be mitigated though as the worms will just avoid the hot areas - as long as it doesn't heat up the entire bin.

Surface Area

More surface area means more microorganisms can colonize the material and more room where the worms can start to eat. Again, this is not necessary, but will help a lot. You can increase surface area of the food you add by breaking/cutting it apart - most commonly and easily done with a blender.

The Unknown..

If these other things are provided for and the worms aren't eating it, its probably for a good reason. Worms are very tiny but very advanced soil testers. It may be too acidic for them (citrus), too spicy (peppers), or have some chemical - natural or unnatural - that they don't like. Maybe there is some sort of herbicide, or salt, or something on the material. Its hard to say and I would have to leave the detective work up to you to figure out what it may be.