Worm composting. See what they do to a corn-flake box.

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Also: Do you have to use worms in compost?

Earthworms in compost good or bad?

Can you put worms in a compost tumbler?

Can you put worms in a compost bin?

Are maggots in compost good or bad?

Can worms live in hot compost?

How many worms do I need for my compost bin?

Worm composting is the ultimate of all composting systems. Worms will always take composting to the highest level when making compost. They are capable of consuming everything that tastes good to them but looks moulded or rotten to us. This is the world of worm composting.

When you see a group of worms squirming around and over each other, you may think that this is organised chaos. You would be right, it is. They follow their noses to wherever the food is and just eat. All of this activity is punctuated by moments of breeding and occasional periods of torpor.

This is what makes worms so useful. When the conditions are favourable to them they get to work for us. They will only eat organic material that has started to deteriorate. Evidence of this will be when there are signs of mould. The worms graze on mould that’s been generated from waste food. Because they have no teeth they find it easy to bite and digest mould, it’s rather like us eating candy-floss.

As the waste food decomposes, the food structure breaks down and softens. This makes it more accessible to worms. They can then begin the process of devouring waste food like an industrial process. This is vermicomposting, When you have a wormery fully set up with a good charge of worms you will be amazed at how much food waste they can consume.

You must be aware that worms can only eat food waste that is either mouldy or well into the rotting process. We have another post that explains more about how worms help with making compost. See ‘Do worms help compost?’

Worms in compost good or bad?

Worms in compost will always be a good thing especially if you are making compost from kitchen waste. Food-waste that’s gone bad, is ideal for worms. They will begin digesting food-waste immediately after the mould-stage has finished. Worms play a big part in compost making, in the early stages.

It’s also a good sign if you see a lively population of worms at work. It means that the conditions are right and that you have achieved the right balance of mixture in the compost. If you don’t get the balance right and there is too much nitrate material and not enough carbon this will hinder the breakdown of organic matter. If the organic matter isn’t broken down enough the worms can’t eat and digest it.

Looking at worm composting

If you’ve got a wormery setup with a good population of worms you will have an ever-open door for all of the organic waste that you have to throw out from the kitchen. The volume of waste that you feed in is limited when operating a wormery but the worms should break it down fast enough.

Green kitchen bucket by Rolypig

This is not the same as a compost bin where you have plenty of capacity. You can throw in larger amounts of waste but don’t expect it to be broken down quickly by the worms.

A wormery will generate both solid and liquid material. Both are of value and can be used as a feed for plants. It would be wise to dilute the liquid with water because if you use it in its concentrated form it may be detrimental to the plants. To make the best use of the solid it would be wise to mix it with sand or soil. Worm castings alone may cause problems. This is a rich concentrated resource it can be spread far and wide making use of what would have otherwise been a nuisance waste.

A dedicated wormery can only work with worms in it. This type of system cannot be used as a composter it is purely a digester where everything must be done by the worms.

Compost bin

Do you have to use worms in compost?

You don’t have to use worms in compost. It’s quite possible to make a really good quality compost relying on just the naturally-provided micro-organisms. Very often worms will turn up in compost regardless of whether you want to use worms for making compost or not.

When you accumulate a lot of organic material and put it in one place e.g. in a compost bin or compost tumbler the material will very often become warm. This is because of the actions of the micro-organisms. Left alone compost will form but it will take longer. Find out more about how to make compost at Rolypig.com.

With no worms in place you will need to have batches of compost forming in a number of compost bins. this would involve filling a bin until you can get no more in it and then closing it off and just leaving it for the micro-organisms and nature to take its time. If you have the space this is an option but you have to accept that these bins will have to be left in place for some time, possibly years.

If you add worms or if worms find their way into the compost at any stage they will accelerate the process. With most composting systems it’s very difficult to stop worms from finding their way into the forming compost. This is because the compost is very attractive to them they can smell it and it’s food. It’s irresistible to them and once they get in and take up residence they will breed very quickly.

Earthworms in compost good or bad?

Earthworms in compost aren’t a problem. They won’t do anything bad to compost. It’s very unlikely that you’ll find an earthworm in compost. Their natural home is in soil. They digest nutrients and organic material that they find in soil. The nutrient-rich material in compost will be too good for earthworms.

The quantity of food in compost would be too much for them because they need soil in the mixture to help them digest the food as it goes through their digestive system. To put it another way, compost is too rich for them. so they tend to avoid compost preferring to stay in the soil where you very often find them when digging over the garden.

If you do see an earthworm in compost it will probably be because the compost is very old. When compost has reached this stage of maturity it will not be too rich for the earthworms and they will be quite happy to live in it.

Worms know exactly what they like and if you see them anywhere it’s because they’re happy to be there and they’re getting what they want.

About worm composting

Worms in a compost tumbler

Most compost tumblers are off the ground. They are usually on a stand to make it easy to roll the tumbler over. Because of this the worms can’t easily find their way in because they have to climb up the framework to get anywhere near the food. This isn’t to say that none will make it because it’s always possible that some will. If you do see any worms in the tumbler that have just turned up by themselves it means that you’ve got some very acrobatic worms.

Can you put worms in a compost tumbler?

You can put worms in a compost tumbler. Don’t roll the compost tumbler any more than you need to and the worms won’t become too agitated. You can put worms in a compost bin or any pile of rotting organic material. You don’t need to bother with spreading out a load of worms that have just been put in the compost. Leave them to spread out by themselves.

It’s very important to note that before putting worms into any composting system that the compost you’re putting them into is suitable for them. if you place them into compost that is warm the worms won’t be happy and they will leave by any way they can.

If the contents of the tumbler are fresh green kitchen waste and nothing else they won’t be happy because there’s nothing there for them to eat.

They can’t eat fresh green waste. So before adding worms to a tumbler you need to wait for the kitchen waste to rot down to a point where the worms can see it as food.

Worm composting

The worms will feed on the mould that develops on kitchen waste in the early stages of decomposition but they need to have enough well rotted compost to live in. They actually need this to have somewhere to hide from predators and to be able to get away from light because worms prefer to be in the dark.

An added complication is that if there is too much fresh waste worms can be affected by the fact that gases are released in the early stages of waste decomposition. These gases are usually toxic to worms and will drive them from the area.

While it is easy to physically place worms into a compost tumbler if the conditions aren’t right for them they will leave by crawling out wherever they can. They will find their way down the tumbler stand and disappear straight into the ground before heading off to find food source elsewhere.

The tumbling action will upset them but, in my experience, it’s never enough to make them want to leave. You only need to roll over a compost tumbler occasionally to get the aeration effect that accelerates decomposition.

Worms in a compost pile

Worms will just turn up in a compost pile when it becomes attractive enough to them. You shouldn’t need to add worms to a compost pile. The only time you may need to physically import worms to put into a compost pile is if the pile is on ground that is totally bare or on concrete or stony ground.

But even if there don’t appear to be any worms around anywhere it is amazing to see how worms will find it because they have a very keen sense of smell. It will only take a handful of worms to find your compost pile, in the middle of nowhere, to take up residence and before long you will find there will be an ever expanding population.

Another important consideration here is that the compost pile must be moist because if it’s dry the worms won’t be able to function. By the same token if it’s too wet, although worms prefer moisture, they will leave for that reason.

You can put worm compost on the lawn.

Can you put worms in a compost bin?

You can put worms into a compost bin just in the same way as adding them to a compost pile but depending on where your compost bin is and what sort of compost bin it is you shouldn’t need to add worms. If your compost bin is open at the bottom, the worms will find their own way in. You don’t need to put worms in a compost bin to make compost. 

This won’t happen straight away. It may take several months of loading waste into the compost bin before you see any worms. This is because, as with any compost, it will take a while for the compost to form and be ready for the worms to take up residence. Also because a compost bin is a confined space the gases that are produced in the early stages of compost being made will be contained. This will deter the worms from wanting to move in, unlike a compost heap that has much more ventilation allowing any obnoxious gases to escape.

Why are there no worms in my bin?

Worms dying in a compost bin

What kills worms in compost? If you have a problem with worms dying in your compost bin you need to check the ventilation. Because of the gases that are generated when compost is being formed it is quite possible that some worms maybe overcome and expire. Other reasons for worms dying are dehydration. Worms need to be moist.

If you put a lot of dry material in the compost bin moisture maybe absorbed buy this material, so adding water maybe the solution. It is unlikely that a compost bin will be too wet especially if it is a compost bin with an open base. If the base isn’t open and there is no free drainage and rainwater can get in, it is quite possible that the worms will drown or leave in a hurry.

If you have a compost bin and there is a population of worms you need to be aware that most of the time you won’t even see the worms. This can sometimes suggest that the worms aren’t there, but they will be. They will be busy feeding deep down in the compost. A good way to test whether a compost bin has an active population of worms is to knock the bin to agitate the worms a little. When you do this they will all start to move because they don’t like being disturbed. When they move hold your ear close to the surface of the compost and listen carefully. You should hear them making a collective slurping noise. This is a good indication that there is life in your compost bin.


Where do worms in compost come from?

When you set up a compost bin and start filling it with food-waste, you are unlikely to see any worms at all. Then, after the food-waste has started to rot, you may see masses of worms. It’s a mystery to some who wonder how do worms get into compost? Let’s look at where worms in compost come from.

Worms are everywhere or at least you can expect them to be everywhere. The point is where you are trying to make compost there will be a perfect haven for worms. If there is soil near by, which there will be if you’re in a garden, there are going to be worms. You will find it difficult to escape them but who would want to?

All you have to do is to create the ideal circumstances i.e. a compost bin of any type, and the worms will go to it and take up residence.

It’s very simple. When you have created a massive food supply for worms it will become too much of a temptation. It will only take a handful of worms to move in to this new paradise. They will live well and start breeding. You won’t see evidence of this straight away. Because they breed very quickly, in the right conditions, it’s quite likely that the first you will see of any worms is when there has been a massive expansion in the population. When this happens your compost bin may have worms all over the inside surface.

Worms escaping compost bin

Worms are very mobile they don’t need to stay anywhere especially if they’re not happy with their local environment. It’s no good trying to keep them in. In a sealed container it’s not practical because there needs to be plenty of ventilation. If you notice that worms are leaving a composter then there will be reasons why they are leaving.

The overriding reason why they are migrating away from the compost bin will be that there isn’t enough food or there isn’t enough food that is digestible for them. If there isn’t enough organic waste material for them to consume they will digest compost that has already been digested to try and extract more nutrients from it.

This can only be done for a limited number of times before all the available nutrients are extracted. This is when the worms will feel the need to move on. In a compost bin the worm population is constantly expanding. There will come a point when the population is so big that it is inevitable that there won’t be enough food for all of them. This is the time when you will see worms leaving the compost bin.

You shouldn’t be alarmed if you see any worms leaving the bin because as long as there is any food at all that can be digested by worms there will be a population of worms remaining. It is highly unlikely that the entire population will leave a compost bin. They do not swarm and leave like bees.

If for some reason the conditions in the compost bin becomes so bad but there is a major exodus it’s always possible that there will be a small population remaining. The reason for the large number leaving will be for a number of reasons. It may be too wet or maybe gas is produced from a sudden abundance of fresh organic material during the early stages of decomposition. If there isn’t enough ventilation than these gases can’t escape. Some of these gases are toxic to worms which means they will feel the need to evacuate.

These are extreme adverse conditions and may only happen occasionally. you shouldn’t worry too much if this does happen because worms are a part of nature and as such are very resilient. They are tough little survivors, when the conditions become more suitable they will return and carry on doing what they do. 

Are maggots in compost good or bad?

Maggots are good for compost. They do much the same work as worms but they’re only going to be in composting material for a short while. The only bad part about maggots is that they will turn into flies which may become a nuisance. You will not make bad compost if there’re maggots in it.

The thing with maggots is that they are a necessary evil and they have to live somewhere. They are very efficient at digesting organic waste which means that they are competing with the worms who are after the same food.

If you want to reduce down your kitchen waste and convert it into compost quickly, maggots will play a big part in the process. The question is do we want the worms to be the masters of the compost system where they build up a strong population or are we happy for them to face the competition of the ravenous maggot?

The main downside of having maggots present in a compost bin is that at some point they will hatch out into flies. When they do you will see masses of flies all around the bin and you may find some will find their way into your house.

So while on one hand maggots will break down organic waste and turn it into compost on the other hand the flies that the maggots generate become quite a nuisance. On balance you are better off without the maggots.

We have a post that considers the issues concerning flies. You can see it at ‘Compost flies’ and judge for yourself about whether they are a real problem.

How do I get rid of maggots in my compost bin?

There are a number of ways to get rid of maggots but you need to find an option that doesn’t adversely affect the worms. The best way that I know of is to use white lime (hydrated lime). This will have the effect of either driving out or killing the maggots. There is an added bonus. If you use lime it will neutralize the acidity in the compost which will make it easier for the worms to digest and process rotting material. The worms will actually ingest small particles of lime which helps with them digest.

Can worms live in hot compost?

Worms can’t live in hot compost. If they can move away from hot compost, they will do so. Worms that are contained in hot compost, won’t live for long. Compost that becomes hot will cool down at a later stage. This will allow the worms to return if they left because the compost was too hot.

Fresh material that’s added to compost bin will tend to warm up in the early stages of decomposition. This is when bacteria are actively breaking down the material in the first stages of composting. If it’s just a small pocket area the temperature won’t rise too high because the heat will disperse throughout the rest of the heap. The heat that is generated won’t last very long.

Worms can only live in material that is cold but above freezing. They are very sensitive about temperature. It is not a problem if there is a hot-spot in a compost bin but it is important that the worms can escape to a cooler part. Here they will thrive and explore the hot spot as it cools.

If there is a comprehensive warming up of a compost bin because of too much fresh organic waste being added in one go this could quite easily be devastating for the entire worm population. If there is nowhere for them to escape to within the compost bin, they will leave the compost bin completely. For this reason it’s very important that you do not add too much fresh material at any one time. If you have a lot of fresh green material that you want to turn into compost place it in a separate container and allow it to go through the early stages of decomposition. This will allow the heat to be generated and disperse without affecting the worms in the main compost bin.

You can accelerate this process by agitating this material and when you’re satisfied that there is no more heat being generated you can then place all of this in the compost bin where the worms are. The same process would work just as well when running a wormery.

How to keep worms in a compost bin

If you stick to the simple rules of making sure that the compost doesn’t get too warm and that there is plenty of free drainage, the worms will not feel the need to leave. The adding of lime will do much to improve the conditions for worms. This is the best you can do and in most cases should be enough.

There is no point taking action to seal a compost bin or wormery to keep the worms in. Doing this you would restrict ventilation and the worms would suffocate. It’s much more important to focus on providing the best conditions you can so that the worms want to be in your compost bin.

Does citrus kill worms in composting?

Citrus material will not kill worms. All that will happen is that they will move away from an area where there is excessive acid coming away from this material. They will stay away from it and only approach it when the citrus material has deteriorated and the acidity has become diluted to a point where the worms feel comfortable.

If there is nothing but citrus material being added to a compost bin then you must take action to neutralize this acid.

Acidity tends to preserve rather like pickling. Instead of rotting into compost it will just sit there without changing for some time.

Worms compost leaves

If you’ve got loads of dead leaves in the autumn/fall, make compost from them. The worms will eat dead leaves when they begin to decompose. The leaves must not be dry because dry leaves don’t rot down so it’s important to soak them generously with water to help accelerate decomposition.

Do not expect worms to thrive in the bin where there are just leaves and nothing else. It’s very important to add the dead leaves to compost that’s already formed and where there is a good population of worms already established. by doing this the worms will find their way into the leaves when they have decomposed enough.

They will break the leaves down completely and turn them into, possibly, the best compost you can make. Because of the potential volumes of leaves involved it would not be practical to feed them to a small wormery because they take up too much space.

You really need to load the leaves into a larger composting system like a compost bin or a compost tumbler. It would be more practical to store leaves in bags and feed them into your composting system a bit at a time.

The ideal way of using dead leaves is to add it to green kitchen waste so that the two become mixed. Dead leaves provide the carbon factor which is just what you want to balance the high nitrate content of green kitchen waste. So if you’ve got any leaves you really should make use of them in this way.

Types of worms in compost

There appears to be two types of worm that get the job done when it comes to turning fresh green waste into compost. If you wake up one morning and find that a population of worms has exploded in your composting device, these will have moved in naturally from the surrounding ground.

They are most likely going to be red earthworms. For those who want the Latin it’s Lumbricus rubellus.


The other one that has covered itself in fame and glory when it comes to turning green kitchen waste into black crumbly compost is the Tiger worm. Also known as the red wiggle worm and the red Californian earthworm. To give it the Latin it’s Eisenia foetida.

Worm castings

The Tiger worm is especially bread for the purpose of making compost and is used to commercially make compost on an industrial scale because it’s considered to be the most efficient out of the two.

If you can identify these worms and tell them apart then count yourself as clever.

We are free to debate which of these two is the best but who cares just as long as there is a good population of worms in the compost breaking everything down and producing something really useful.

If red earthworms have moved in and taken up residents and they appear to be getting the job done, there’s no point introducing Tiger worms.

Life cycle of worms in compost

The worms lay ‘eggs’ which are more commonly known as cocoons. They hatch into tiny little worms and reach maturity in around one month. It’s from here on that all the fun begins because apart from spending most of their time eating, they have the advantage of having both male and female organs. This gives them plenty of options in their mating habits from which they generate one or two cocoons every week.

3 weeks later 2 to 3 worms will emerge from each cocoon. This goes some way to explaining why such a big population of worms will appear in a short time. As a rough calculation every worm in a compost bin has the capability of producing around 600 more worms in its lifetime.

In good conditions a strong population of worms will double every three months so if you imagine the point where there are 500,000 worms, in three months time there will be 1 million. I’m not suggesting that you count them out but it is an interesting thought.

Worms compost winter

Worms will not survive below 35 degrees Fahrenheit or 2 degrees Centigrade. The maximum temperature they can cope with is 75 degrees Fahrenheit or 25 degrees Centigrade. The cocoons however will survive where are the worms won’t. They have their limits as far as temperature goes but they will cope In adverse conditions enough for a population to be regenerated.

In extreme conditions the worms will migrate away from areas of cold or heat. Where there is a reasonable mass of compost material it is well possible for them to find an area in the middle where they can survive comfortably.

If the volume of compost is large enough the inner volume area will be insulated enough to provide a winter refuge. they will stay where they feel safest and most comfortable until the conditions change following the seasons

Another factor is the moisture level. Worms don’t like being dry, they need moisture to stop their skin from drying out. It also provides lubrication for moving through the compost material. Moist material is easier for them to consume.

What what are worm castings

Worm castings can be thought of as an organic form of fertilizer produced by worms.

This is what are the worms produce when they eat and digest organic waste. Because they are eating all the time they are producing worm casts all the time. A pound of worms will digest half a pound of material every day and produce worm casts from it.

Because of the nutrients in the green organic waste material you can safely assume that, even though it’s been through a worm producing worm casts, that this will do a lot to feed plants. After having been thoroughly digested by worms there will be a range of available nutrients which plants can make use of straight away.

Worm farm

Worm casts, also known as vermicompost, can be made quite easily. There are a number of ways in which you can do it. You could set up a wormery or you can get pretty much the same effect using a compost bin but with this method you would need to have a closed batch system. This is because you need to be able to leave the compost long enough for the worms to convert the whole amount completely.

It’s very important that you don’t add any fresh material after the closing off point. this way you will end up with a consistent organic fertilizer that won’t be contaminated with any fresh waste material.

It’s not practical to try and make vermicompost using a tumbler-style rotating composter. This is because worms don’t like being disturbed. They don’t appreciate being mixed around with everything around them as though they were in a concrete mixer.

If you have a rotating compost bin and you want to make vermicompost the best thing you can do is to get a compost bin to put beside the rotating bin. when you have fresh waste from the kitchen load rotating compost bin and rotate it regularly.

When the rotating composter is full have a shut off point where you don’t feed any more fresh material for a while. Maybe have a holding-container to store waste in the meantime. This is to give the most recent addition of kitchen-waste a chance to rot down enough for the worms to start digesting and converting into vermicompost.

At this point remove the entire contents of the rotating composter and place it in the empty compost bin. If you are lucky some red earthworms will seize upon the opportunity and migrate into the compost bin. They will then begin to digest the contents.

With the rotating composter empty you can now start loading it again every time you have waste from the kitchen to dispose of. When the rotating composter is full just repeat the whole procedure until the static compost bin is full.

At this point it may be necessary to have an extra compost bin to allow the worms in the first compost bin to completely convert the contents to compost.

If you have a Rolypig composter you won’t need to stop feeding in waste at any time because the waste goes in one end and emerges at the other. It’s a constant throughput system. But it may still be an option to have a compost bin to go with your Rolypig because what comes out of a Rolypig could be further refined allowing worms to completely break the compost down into vermicompost.

Slow worms in a compost bin

Slow worms are often mistaken for snakes but they are actually a member of the lizard family. They are lizards without legs. It’s relatively unusual to find a slow worm in a compost bin but if there is a warm spot in the mass of material, this is what will attract them.

The slow worm

Their normal habitat Is among dry sticks or rocks, generally anywhere where they can hide from predators. They are carnivorous themselves and pray on slugs which makes them useful in the garden. They also like worms, so if you see one in the compost bin it’s probably a good idea to remove it. Take it to somewhere away from the compost bin and place it in long grass where it can slither off and hide.

If you know you’ve got slow worms around be prepared to see them regularly as they have a lifespan of anything up to 30 years and they can grow up to half a metre long.


How many worms do I need for my compost bin?

You need as many worms as your compost bin can provide worm-food for. We could pick a figure out of the air and say that you need one and a half pounds of worms per square foot of compost bin-space but if you start with a couple of pounds of worms, you will find that they will breed up to match the amount of compost in your bin.

You don’t need to buy large quantities of worms. The minimum quantity that’s available will be all that you will need for a compost bin. If you want to know how many worms you’re buying, someone’s apparently done a worm-count and discovered that 1lb of red worms consists of 1,000 worms.

Who among us would actually want to know how many worms make up 1lb of worms? I haven’t looked to see if there’s any hard data that shows that 1lb of red worms consists of 1,000 worms. 

I suspect that someone asked the man in the worm-shop: How many worms do you get in 1lb of red worms? They’re sold by weight, not volume, so his reply could easily have been ‘oh, there must be about a 1,000’.

Knowing how many worms are in your compost bin is something that no one needs to think too much about. If you buy the minimum quantity of worms, you don’t need to be too concerned about how many worms are there. You only need to make sure that they’re alive and wriggling around.

Whatever number of worms that you have, you can be sure that they will breed. Give it a few months and the quantity of worms that you bought will have exploded into a vast number.

Any worms in your compost bin will breed up to become enough worms for your compost bin’s needs.

If you’re prepared to wait for worms to turn up in your compost bin, they will move in from the ground. This is more likely to happen if a compost bin is seated directly on the ground and the rotting food-waste itself has ground contact. 

When the food-waste has rotten enough, the worms will become interested and move in. It won’t matter if just a few worms move in. You may be unlucky and there are no worms in your area that consume and break down food-waste. This problem will, most likely be due to the type of soil that your compost bin is situated on.

You may be able to find worms by digging around in soil where there are rotting leaves or other types of rotting vegetation. Gather as many as you can. 

If you know someone who has a compost bin with a good population of worms in it, ask them if you can have a bucket of compost. You won’t know how many worms there will be in a bucket of someone else’s compost but you can be sure that it will make a difference to your own compost bin.

Every worm will count, when placed in a compost bin that’s got rotting waste in it. They all have the ability to multiply and will do so, rampantly, in the right conditions in a compost bin.

To sum up:

Worm composting

  • Anything that’s food to us will be food to worms

  • Worms will keep going until they’ve broken down every crumb of food-waste

  • They will only eat food-waste when it has started rotting.

  • Worms will multiply to match the quantity of food-waste available

  • As long as you keep feeding them, they will keep thriving

  • Worm composting will provide you with a black crumbly compost that will beat all others

The worm makes life below ground just

as busy as life above”

To Home Page

 Composting. Find out about the basics. Find out if a composting toilet is for you. How to deter rats from garden

 Rat proof garden. Is it possible? Snakes in compost bin Balcony compost

Can you put cooked meat in compost? Bokashi soil factory Compost flies

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