This post is only one part of a series on the topic of ‘Composting in Deserts and Drylands - The Complete Guide’. 

In this post I would like to focus on the challenges and the solutions of vermicomposting systems in deserts and dry climates of the world. The information and resources I will share here includes everything you will need to successfully set up, maintain and troubleshoot your own vermicomposting system in the dry climate areas and deserts of the world. 

Note 1: ‘Worm farm’ and ‘vermicomposting system’ will be used interchangeably throughout this post, and both refer to non-commercial systems for home use, although it could be easily applied to larger commercial systems. 

Note 2: There is a difference between ‘composting’ worms and ‘earth’ worms. Here we will talk exclusively about composting worms. 

To start off with, I would like to share a video with you, which I believe is a quick and easy intro into the topic.
It is an 11-minute video created by my personal teacher, Geoff Lawton, who is a permaculture legend, and a master gardener and compost maker. 
In this video, he explains in detail how he sets-up and maintains his personal vermicomposting system, and it is a fantastic resource for anybody who is either new to vermicomposting, or for those who would like to brush up on their knowledge and skills. 
 
So let’s start off by watching this video, and then I will get into more details pertaining to vermicomposting success in the desert. 

In regards, to what Geoff shared in the above video, I would like to add a few sidenotes: 

He used a recycled bathtub as the basis for his worm farm, but you could use any sort of container, if it can drain well, does not corrode, and keep the worms safe and protected from the desert elements (more on that later). 
You can adjust the size of your vermicomposting system according to the quantities of organic materials you plan to process. 
If you follow the basic ideas and processes that Geoff shared and the desert related adjustments I will cover here, you can create and modify the size and set-up of your vermicomposting system according to your personal needs, preferences and resources. 

Now let’s discuss the challenges we face with vermicomposting in the desert and explore some solutions. 

1) Temperature 

Temperature fluctuations and extremes are some of the biggest challenges faced in dry climates. Composting worms do not do well in extremely cold or hot environments. 
Therefore, it is vital that you set up your system in such a way that they are not affected by this. This can be done in various ways. 

The first solution would be to keep your worm farm in a location less prone to temperature fluctuations and extremes. For indoor systems, this is easily achieved. We kept our worm farm in the garage for over a decade, and they were always happy. 
Outdoor systems should be placed in well shaded, and wind protected locations in your garden. Avoid placing them in direct sunlight and the associated heat. 
In-ground vermicomposting systems such as this one work well in dry climates, as the surrounding soil keeps temperatures in the system stable. 
For an above-ground system, additional thermal protection should be considered. Most insulating materials could be used. We prefer materials such as straw bales and cardboard, as they offer a cheap, easy to use and natural insulation solution, that can then be composted when they reach the end of their lifespan. 

2) Moisture 

Composting worms need oxygen, and they breathe through their skin. To do so, their skin needs to be always moist. If they dry out, they die. The same is true if they are submerged in water. 

In our dry climate, maintaining adequate moisture will be our biggest challenge. Here are a few ways to prevent the system from becoming too dry: 
 
Construct your worm farm from materials that contain moisture and do not wick it away to the outside. In our desert context, a wooden worm bin would be a poor choice, as the wood constantly absorbs moisture from the inside of the system and evaporates it off on the outside.  
Plastic containers are commonly used, although others (like Geoff’s recycled bathtub) may do an equally good job. 

You can further prevent evaporation by adding a barrier over the top of the organic material in the worm farm. We use a few layers of damp newspaper or burlap bags, but old carpets, old cotton cloths, clothing and towels, etc. will all do the job. Just remember to use things that will not leach chemicals into the worm farm, and that allow for some airflow and gas exchange. 

Another solution is to add water rich fruit and veggies more regularly, as these will regulate moisture levels over a longer period. 

In extreme cases, one or two drip emitters could be linked into your irrigation system, and these could add additional moisture on a regular basis. 

Too much water can be an issue also, as the worms will drown, and an anaerobic condition may occur. To avoid this, make sure that your system has adequate drainage. Also, place your system somewhere where it will not get flooded when rain and floods do occur. 

Whatever system and material you choose, make sure that it still allows for draining of liquids from below, and air circulation from above, whilst minimising evaporation from the inside. 

 3) Pests 

As with other composting systems in dry climates and deserts, any excess moisture and food relative to the surrounding environment will attract all sorts of creatures. Keep this in mind when choosing or building your own system. 

The best way to deal with this is to place the system where it cannot be reached by these creatures or protect your system by using physical barriers. These will vary depending on the types of pests you attempt to exclude from your worm farm. 

I would like to add that most so-called pests will not harm the worm farm, and that our only problem with them lies in our social conditioning towards them. 

 4) Light 

Whilst this is not unique to deserts or dry climates, it is a vital part of a well-functioning worm farm, and as such it will go hand in hand with the 3 challenges listed prior to this. 

Worms love the dark, and they will always hide from light. Therefore, make sure that your system excludes as much light as possible. 

Setting up a worm farm in the desert 

There are a few basic components to any worm farm: 

1) Their home (the container, cage, hole in the ground, etc.) 

Worms are easy to please, and if their basic needs are met and they have a comfortable environment in which to live, eat and reproduce, then they will keep making that amazing vermicompost for us. 

Which vermicomposting system is right for you? 

There are a big variety of worm farm systems available these days, and it sure can be tough to know which one is right for your needs. Let me try and give you a little guidance. 
 
Indoor systems are a great solution for anyone in an urban setting without access to outdoor space to set up a more elaborate system. They are generally small and compact, easy to maintain, and will easily process all the kitchen scraps for up to 6 people. They are easy to manage in dry climates due to being indoors. 
Our family of 4 used an indoor vermicomposting system for many years. It consisted of three trays, which makes harvesting the worm castings a quick, clean and easy job. We kept them in the garage. 
 
Outdoor systems are a good solution for anybody that has the space, and who wishes to process larger amounts of organic waste. Perhaps they have a commercial kitchen that produces lots of food scraps. Or they have a garden that produces lots of yard waste. Either way, these larger outdoor systems can easily be built and scaled up or down according to the quantities of inputs you have. 
They are also useful for the processing of materials you would not wish to take inside your home, such as decomposing animal-based products and manure. 
In dry climates, maintaining an outdoor system can be a bit challenging, but it is possible if you follow the guidelines in this post. 

In 2019 I was introduced to an in-ground vermicomposting system at the famous ‘Greening the Desert’ permaculture demonstration site in Jordan. That same year they installed the SubPod vermicomposting system and the fact that they are still using it to this day proves that it is a very adequate system for the harsh desert environment. I wrote a post explaining the SubPod system here. 
 
A variety of indoor and outdoor vermicomposting systems can be bought online or through local suppliers. Alternatively, you could set up your own DIY system. A quick google search will return plenty of DIY ideas for creating both beautiful and functional vermicomposting systems. Just remember to build them appropriate to our dry desert climate, and the challenges this climate presents. 

2) Bedding Material  

The bedding material can be any organic material that provides a base food and habitat for the worms. It needs to be relatively loose and allow for air to move through. Dense and waterlogged materials are not ideal. 
Here are a few to consider: shredded cardboard, coconut coir, wood shavings and sawdust, aged horse and cow manure, natural fabrics, finished compost, etc. 

When adding dry materials, make sure to soak them first. 

Avoid anything that may contain chemicals, toxins or any forms of non-organic materials. 

Rather add too much bedding than too little, as it serves as a great food source when there is not enough ‘fresh’ food. 

3) Food / Habitat 

What should you feed your worms with, and what should you avoid? 
The short answer: You can feed your worms any organic and bio-degradable material, within reason. 
 
Let me elaborate: 

Plant based kitchen scraps and yard waste, and anything made from organic or biodegradable materials can be fed to your worm farm; no problem. If you plan on processing a lot of material, then gradually increase the amounts over time, to avoid over feeding the worms and having a surplus of rotting food in the system. Allow for the worm populations to self-regulate over time. 

Citrus, onions and anything spicey should be added only in small amounts, and only once worm populations are fully established within the system (about 2 to 3 months after system creation). These are thought to be quite harsh on the guts of the worms, therefore you would do well in keeping these to a minimum or composting them in other ways. 
 
Meats and other animal-based products could be put into a worm farm in small amounts; however, they may take longer to be processed and as a result pose other risks to the system. Although this has been proven to be possible, many will advise against it. 
Others advise pre-composting animal-based products using the bokashi composting method first, and then adding the resulting material to the worm farm. This works well, as the fermentation process breaks down the material into a more edible form for the worms. It also makes it less appealing to other pests that would normally be attracted to the animal-based products in their fresh state. 
I would recommend doing this in outdoor systems only and in doing so, avoiding any potential unpleasantries within your home. 
 
All oils should be avoided. 

In-organic, chemical or toxic materials should be avoided. 
 
All materials should be chopped or torn into relatively small pieces so that worms can process them faster. They should not be liquid though. 

Try and keep the food varied, as too much of one ingredient can upset the balance of the system. 

Pay attention to what the worms seem to like and what they seem to avoid and adjust your feeding accordingly. 

4) Worms & Microbes 

Once you have all the other parts of the system in place, it is time to add the worms. Make sure to get composting worms, and not earth worms. They are different! 
If multiple varieties are available in your area, add them all in, and the most adequate will survive. They may even work well together. 

The microbes will already be within the medium that your worms live in when you get them, and their populations will grow automatically as the worms do their thing; nothing to do here.

Can you add Dog, Cat or Human manure to your vermicomposting system? 

The worms will love it, yes. I even wrote a separate post on an interesting vermicomposting system for flushing toilets. 

HOWEVER, do not include any human or pet manure in a worm bin that is located close to any edible plants you wish to consume in the future. The same goes for any system from which you will harvest worm castings or worm juice/tea to water and fertilise your edible plants with. 
Also, do not add any type of manure to indoor systems. 
 
If you are unsure, then do not add them to your worm bin, and rather create a second system in a safe location, dedicated to non-herbivorous pets and human manure. 
 
DISCLAIMER: Making a mistake here could cause serious health issues. Therefore, I would highly suggest seeking the help and advice of a professional regarding this topic. 

What to do when you go on vacation and can't feed your worms for a while? 

Worms thrive in the manure of herbivores such as cows and horses. It serves as a great food base in case fresh ingredients are not available. Adding a good amount (depending on the size of your system) before going away for long periods of time will keep them happy and alive. 

For shorter periods, it can be as simple as cutting a few pumpkins, potatoes or squashes in half and laying them on the bedding material, with the insides facing down. Due to their harder texture and large size, this will keep the worms busy for a few weeks. 

In the desert, keeping them moist enough will be a bigger challenge than keeping them fed. This is where it could be useful to have somebody take care of them. If this is not an option, adding an automated watering system such as a drip-emitter from your irrigation system would be appropriate. 

If it does go wrong and your worms die, then it is not the end of the world. In many cases, the worm's eggs will still be there, and once conditions are right again (moist enough), they will hatch and repopulate the system over time. Just be sure to give them some time to rebuild their population before giving them large amounts of food. 

Troubleshooting your vermicomposting system 

Vermicomposting systems are generally easy to maintain, but problems may occur as we are working with a living and dynamic system. Here are some of those problems: 

Smells 

Rotten smells are an indication that too much fresh organic material is added to the worm farm and that the worms are still too few to deal with such amounts. You can fix this by removing the rotten materials, and gradually increase the inputs over a few weeks, so that the population has time to grow to an appropriate size. 
Another cause might be anaerobic conditions forming in the bottom of the container. Check that the drains are unblocked and that any access water can drain freely. 

Acidity 

Worms seem to want to escape? Is mold forming in the worm farm? These can be signs that the worm bin is too acidic. Add more alkaline or materials a neutral PH to the farm.  

Worms trying to escape 

Worms on the run means that something is not quite right. As mentioned above, this could be caused by high levels of acidity. 
An environment that is too wet may also cause this and is often caused by locked drainage. 
The worms might try to escape due to a buildup of noxious gases. Make sure there is sufficient ventilation (without causing access evaporation). 
Lastly, when a lot of fresh material is added all at once, it could heat up in a similar way to a traditional compost heat does. This heat will cause the worms to try and escape. 

Noise & Vibrations 

Although you may not see any obvious physical effects of noise and vibrations on your worms, be assured that they prefer a quiet location, much like that which they would naturally occupy in nature. 

Insects, maggots and other critters 

Some are beneficial to the system. Most of these are only annoying and will not affect the worms in the long term and should not cause any problems for the system itself. If any of these do get established in big quantities, or if you notice a drastic decline in your worm population, then it would be advisable to research more in-depth ways of dealing with whatever the pest has gotten into your system. 
Due to the fact that there are so many different ones, it is not within the scope of this post to list and discuss them all in further detail. 

Conclusion: 

As vermicomposting is such a broad topic, there are a lot of small details and nuances that could be added over time. 
As such, I would like to encourage you to share your personal experiences, thoughts and any questions you may have in the comments below. Pictures of your system are more than welcome also. 
Doing so would be of great help to others that visit this site for guidance, and it allows me to elaborate on this guide over time with the aim of making it as complete and useful as possible. 

I hope that you find this guide helpful and informative. 
To return to the main guide, use this link. 

Thank you for your time and see you in the next one.