Compost Worms (vermicomposting)

Breeding and using worms is called ‘vermiculture’ and using them for composting is called ‘vermicomposting’ and like so many things, can be as simple or as complex as you want. This page and the links in it is a general guide to the things that we’ve found keep them happy at Ligaya Garden.

Keep your worms in conditions where they are happy and can eat and reproduce without too much disturbance and you’ll be rewarded with a rapidly growing population that you can put into another worm farm, let go into the garden or feed to chickens, fish and reptiles. You could sell a few of them or their castings or just take a few of your worms fishing…

The hardest workers in the place.
The hardest workers in the place.

What are compost worms?

Eisenia fetida, otherwise known as ‘Tiger Worms’ or ‘Red Wrigglers’ are just about the best composting buddies a garden can have. They work tirelessly, day and night, helping to break down our veggie scraps and green waste into castings and liquids that are second to (almost) none in terms of adding nutrients to soils and grow media.

Composting worms are not the same as the Earthworms you find in soil and need different conditions to live.In the wild, they live close to the surface of the ground, in or just below organic material that needs breaking down. They can don’t like to go below about 15 cm from the surface.

Breeding and using worms is called ‘vermiculture’ and using them for composting is called ‘vermicomposting’ and like so many things, can be as simple or as complex as you want. This page and the links in it is a general guide to the things that we’ve found keep them happy at Ligaya Garden.

Keep your worms in conditions where they are happy and can eat and reproduce without too much disturbance and you’ll be rewarded with a rapidly growing population that you can put into another worm farm, let go into the garden or feed to chickens, fish and reptiles. You could sell a few of them or their castings or just take a few of your worms fishing…

Worms have the joy of living in their food.
Worms have the joy of living in their food.

Red Wrigglers are undemanding critters, they like to be in a dark, moist place with a fairly constant temperature and to have constant supply of food available.

Worms have the joy of living in their food. They pass through it again and again, eating the decaying material and bacteria and fungi that colonize it. As they do so, they pass out bacteria rich liquid and solid material (known as ‘castings’) which is pure gold in terms of giving the garden a boost.

What do worms like?

Worms like the pH of their environment to be slightly alkaline, between 7 and 8, so they don’t enjoy acidity in general (maybe you’ve put a whole bunch of citrus in their bin recently?). This can be remedied with a pinch of dolomite or lime added to the bin with every feed. They’ll eat the overly acidic food it eventually but will leave it to last. Many bacteria produce an alkaline environment for themselves as they decompose food and this will helps the worms to access the acidic food eventually.

We’ve noticed an exception to this general rule though. They love Bokashi vegetable scraps and will suspend their dislike of acidity to feast on these very quickly. When I add this kind of scraps though, I do it in small amounts and mix a little dolomite, crushed eggshells or bicarbonate soda in with them to reduce that acidity a bit.

Of course, they don’t like drying out, too much light or being eaten by predators either. These things are easily remedied, with the last often being caused by adding too much food at once. What the worms can’t eat sits on the surface, attracting, mostly, ants and rats.

One way to ensure constant dampness while blocking out the light and allowing air to flow to the worms is to cover the top of the bed with an old sack or piece of hessian. This also has the benefit of insulating the bed during weather extremes.

This is what it's all about...precious castings
This is what it’s all about…precious castings

Tips for keeping happy worms –

These tips are mostly for the raised bed kind of worm farm but generally apply to in ground worm farms such as trenches and worm towers too.

  • Don’t put too much food in at once. This is something you’ll have to work out by trial and error. Feed them small amounts regularly. This allows the worms to do their job and keeps the worm farm clean.
  • Don’t let the bin get too dry or hot. Worms hate the dry. As long as you can squeeze a pinch of castings between finger and thumb and to form a malleable ball, that’s OK. If your worm farm gets too hot or dry, the worms will migrate downward to the cooler areas. If your bottom layer isn’t well drained, or there is no way for the worms to escape, they will drown en-masse. That makes for a smelly clean out!
  • Don’t let the bin get too wet. Worms can drown. a great way to keep the bin from flooding is to leave the tap or outlet open all the time. You’ll find a few adventurous worms escape that way, but its better than opening a bin full of dead and decomposing worms. That stinks!
  • Keep some dry bedding in the worm farm. This gives the worms a chance to move from areas that are too wet. It also works its way into the castings, allowing a degree of aeration.
  • Keep the pH around 7. It can go a little closer to 6 with no worries, but worms don’t like extremes. The little fellas breath, feel and communicate through their sensitive skin. Imagine their dismay when they crawl into a patch of acid! Adding a pinch of dolomite or lime to the bed helps with acidity. Put some citrus in when it’s too alkaline
  • Keep the light out. Worms are photophobic and don’t enjoy the light. A close fitting cover, some sack or other breathable material can do the job just as well.
  • Add some grit such as fine sand from time to time. This helps the worms break down the food in their gut and makes for healthier worms.

Notes about feeding –

Chop the food into small chunks. The smaller the pieces of food, the quicker they break down and the quicker the worms can eat them. You can blend your worm food too and add the sludge. Just don’t add too much at once.

A way to speed up the access of worms to the food is to freeze it first. Freezing expands the water in its cells and bursts them. Once the food has thawed out and you put it into the worm farm, they will be able to eat it more easily.

Don’t add too much food at once. Smaller amounts a couple of times a week are better than a bucketful all at once. This helps the worms get to the food before it goes off and causes problems.

Put the food in one place, don’t spread it all over the surface. This encourages the worms to get together and when they’re together, they reproduce.

Worms escaping
Stretching their legs a little…

The main problems in a worm farm are…

The bin worm farm is too dry

This often happens in the warmer weather if the lid of the worm farm isn’t on properly or the worm farm is located where it gets too much heat from the Sun. You may have to move it to a shadier location, slowly increase the moisture level by sprinkling on water at regular intervals. A damp sack placed on the surface of the top bed works a treat at keeping the topo bed cool and moist. Make sure your lid is a good fit too.

The worm farm is too wet

This problem can cause food not to decompose, which can be the cause of some of the other problems addressed below. It can even suffocate or drown your worms. Often too much moisture is caused by a poorly located worm farm receiving a lot of rain. Changing the location is a must in this case.

It can also be a problem caused by putting in too much food, especially wet food and goodies that contain a lot of moisture. Remove a lot of this and store it to add again later or feed it to your chickens.

One more cause could be a closed or blocked drain tap not allowing liquids to leave the worm farm. Leaving the tap open at all times helps with this.

To remedy a wet bed (pun intended), mix in shredded paper or well chopped straw and let that absorb some of the moisture. Extreme cases can call for dried coir peat to be mixed into the affected layers. Dry bran can also help but it tends to attract mould and can even heat up a bed as it breaks down. This is great in winter but can be devastating in Summer.

The worm farm is too acidic / alkaline

You can often tell from the presence of other problems whether your worm farm is too acidic or too alkaline. The remedies are quite simple. For acidic conditions, add substances that break down in acid such as crushed egg shells or dolomite. These are great because they add minerals to the worm’s diet too.

For alkaline conditions, adding more citrus scraps such as orange peels can help. For a faster solution, a light spray with vinegar, especially Apple Cider Vinegar or even Kombucha can help. Be sparing though, it is easy to add too much and it seems to be easier to tip conditions toward the acid side of things.

Our worms love love love the Mother from Apple Cider Vinegar or the SCOBY from Kombucha. Both are a touch acidic so will help with the balance but mostly, they love the yeasts and bacteria that live on them.

Escaping worms

Worms have no choice but to move away from sources of discomfort. They live in their food and sense their surroundings through their skin. Areas that are too extreme in many ways will cause the worms to migrate away.

They will also migrate to the upper surfaces of the worm farm when the air pressure drops just before it rains. This is nature’s way of keeping worms from drowning when the soil gets drenched. The lower air pressure causes them to move up out of the soil or compost.

However, worms like to move around, going on little worm forays to check out the surrounding area. If you have a few of them on near the lid, as in the picture above, they are probably not escaping, just wandering around. Don’t worry if you see this from time to time.


There can be several causes of a worm farm smelling. Too much food that’s just rotting on the surface is the main culprit. It can also happen if you add rotting or decaying food like meat or fish to the worm farm. Too much moisture is the next in order. This allows anaerobic digestion to occur which can be nasty. Third is, maybe…sadly…your worms are dead. This happens, so check regularly just under the food layer for lots of red, wriggly, happy critters.


Remember, first, that a worm farm is an ecosystem of its own, with producers, grazers, predators, fungi and bacteria. In balance, they don’t cause a problem, but its when any of them occur in huge numbers that there is an issue.


Green mold
A little mold isn’t too bad.

Mould isn’t bad in small amounts, it’s another way that your food scraps are being broken down. You’ll find it on pieces of bread or pastry that hasn’t broken down yet. The solution is to reduce the size and amount of breadstuffs you add to the bed and bury the bread completely. If you have a lot of mould, take care if you disturb it, it can release clouds of spores that could cause respiratory if you breathe them in. Best to wear a mask and cover the mould with fresh food or castings.

Slugs or Snails  

Poor sealing of the bed is usually the cause. Slugs like to live in the same conditions as worms, so will often be found breeding happily in your worm farm too. Manually remove them and give them to your chickens.

Red mites  

Little red crawling dots that are related to spiders and can attach themselves as parasites to your worms. These are attracted by acidic conditions. A little dolomite will help here to sweeten things a little.

Little black flies  

These are Fungus Gnats and are attracted to decaying fruit and vegetables. I’ve never seen a worm farm without a few so don’t panic they aren’t usually a problem. They love moisture, fungus and free food so removing excess foodstuffs and adding some dry bedding material to your worm farm will help reduce their numbers. You could also leave the lid of your worm farm slightly open to help dry the top layer of the food stuffs out a little.

Fruit Fly

These are the same flies that cause problems with fruit on trees so it’s important to keep them under control. They are small flies with light brown to yellow bodies and, as their name suggests, are attracted to the decaying fruit in your worm farm. To keep them at a minimum, keep the bin well sealed and bury fresh fruit scraps completely. In fruit fly outbreaks, I’ve caught quite a few using a commercial fruit fly trap suspended above the bin.


The larvae of flies.These are a problem and point to too much food lying around. They are excellent decomposers and can eat a lot of material so they can compete with your worms for food. Keeping the bin well sealed and drying things out a little will help reduce the likelihood of you getting infested with them. Your chickens will appreciate them.

Little white worms 

They can be seen all the time, but don’t usually cause a problem. They are called entrachydids. They indicate acidic conditions.


Ants are the supreme opportunists. They will invade a worm farm at the first opportunity. Too much food, or feeding meat or fish to the worms is usually the cause.


Not usually a problem unless they’re in plague numbers. They’re detritivores so eat the same food as the worms. Generally, having a few around is a good thing.


Spiders show us that there is a thriving ecosystem with lots of prey but they do prefer dry conditions. Here in Oz, Redbacks like to live in corners of the beds, and live to live where the legs of the worm farms attach to the body. They also love to live in the folds of dry sacks that cover the surface of the farm and have been allowed to dry out. So keep the worm farm a little moister if you have too many Spiders in it.

It might seem like keeping a worm farm is a juggling act – wet/dry, acid/alkaline – its all got to be balanced but things often work out for themselves. Your worm farm is a dynamic, living ecosystem that responds to conditions inside your worm bin as well as those outside of it. Feed it well, keep it clean and moist and all should be well.

There is actually a plus side to most of the pests that you will find in a worm farm – chooks love them. Incorporate your chooks into your worm ecosystem as the top predators (of course, feed them outside of the worm farm…they love to eat worms just a little too much).

Keeping your worms cool in Summer

Keeping your worms warm in Winter

Worm Towers

Worm Teas

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