We are such big fans of worm-farming that we now have four: two hungry bins (a continuous flow-style worm farm) and two worm cafes (tiered-style worm farms).
Worm farms are everything that conventional composting should be: simple, fast and clean. Unlike compost bins there’s no turning required, no smell and they don’t take up much space. It’s really a set and forget kind of system – they’re without doubt the lowest maintenance ‘pet’ you can have.
Worm farms produce the holy grail of compost – worm castings – and all for free using the by-products from your kitchen.
They are truly a one-size-fits-all solution: whether you have a fully fledged fruit & veggie patch, an indoor plant collection, some pots of herbs on a balcony or courtyard, or lots of flowers – worm farms are an absolutely essential part of a flourishing and sustainable garden!
Benefits of worm-farming
- My favourite reason for worm-farming is its ease – less than a minute’s work each week
- No smell – worm castings do not have any smell, and a properly maintained worm farm is odourless
- No heavy turning unlike conventional compost bins – the worm do all the turning for you
- Being an enclosed system, keeps out mice and rats
- Produces the holy-grail of compost: worm castings – a fancy word for ‘worm poo’ and often referred to by gardeners as black gold
- Worm castings are a free, concentrated soil fertiliser that plants simply go nuts for
- Allows us to ‘close the loop’ on our food waste and scraps, turning waste into free fertiliser for the garden
What’s all the fuss about worm castings?
Worm castings are the absolute pinnacle of garden fertilisers, which is why you’ll sometimes hear worm poo referred to as ‘black gold’. In my experience, plants fed with worm castings vastly out-produce their peers, and are more disease-resistant and drought-tolerant. My corn plants that were fed worm castings produced larger and more cobs per plant than those that didn’t get the benefit of this black gold. They give a huge boost to young seedlings.
Worm farming vs Traditional compost bins vs Bokashi
Worm farming in essence is a type of small-scale intensive composting. However, it is different to both traditional compost bins and Bokashi. Each of these systems are complements to each other and do slightly different things. The simple way I like to think of it is:
- Worm farms produce a concentrated form of compost, more akin to a ‘fertiliser’
- Composts produce large volumes of bulk material i.e. the compost/soil for plants to grow in, and
- Bokashi bins produce a half-fermented product which then needs to go into a worm farm, compost or be buried in your garden to finish decomposing. Effectively a bench-top ‘fermenter’.
The table below summaries the key differences between each of the systems, the pros and cons, what inputs go in and what outputs they produce.
|Type of composter
|I give you
Great for everyone: apartments, gardens – small and big
|Mostly kitchen fruit and veggie scraps, coffee grounds, adding small amounts of leaves, newspaper, cardboard etc. Tolerates limited citrus and acidic scraps.
|Fertiliser – concentrated
|Clean – no smell
Easy – no turning of materials
Fast – produces worm castings quickly
Keeps out rats and mice
|In my opinion none!
Not suitable for apartments, more for gardens
|Bulk garden prunings, spent plants, chicken poo, mowed grass, leaves and also kitchen fruit & veg scraps. Add excess citrus to the compost bin.
|Bulk material for plants to grow in i.e. soil
|Processes and produces large volumes of garden materials
|Takes up a fair amount of space
Requires regular turning
Could turn smelly if the balance isn’t right or not well cared for
Can become a home for rats
Great for apartments or any household
|All kitchen scraps, cooked or uncooked, also leftover meals, meat and dairy.
|Half-fermented output that needs to be added to a worm farm, compost bin or soil to further decompose before using
Liquid needs to be heavily diluted before use to ‘fertilise’ plants
|One of the only systems where you can put animal products, bones and dairy
Compact – fits on a benchtop
|Not a finished product – needs further decomposition before use
Has a smell – ranging from acidic and fermented to stinky
Small ongoing cost through purchase of fermentation powder
In summary, if you’re in a small living space, such as an apartment, then compost bins generally won’t be practical, but worm farms and Bokashis are still great options. If you have more space to work with, then you should consider adding a worm farm as a complement to your existing compost bin.
How much work is worm-farming?
It is actually very little work. Do you have 30 seconds to spare a week? 30 seconds or so is all it takes to walk up to the worm farm, dump some food in and have a quick look to ensure everything’s going smoothly. Unless you’re like me and find them fascinating and find yourself opening the farm just to check on your little worm pets … that takes a bit longer.
In summer, you’ll need to put in some frozen food on super-hot days. A few times a year you will need to spend a bit of time harvesting the vermicompost. It’s much less work than a compost bin because there is no turning of heavy materials! And the longer you do it the easier it gets, until it becomes habit and fits seamlessly into your lifestyle.
How much is this all going to cost me?
There are heaps of great DIY options to make your own worm farm using a polystyrene box or esky – it will cost you next to nothing to upcycle. For those less handy or time-poor you can purchase a pre-made worm farm for very little.
In Australia, depending on your council area, you might be able to get them at a discount from Compost Revolution. You can also get second hand worm farms off Gumtree – often complete with worms! Depending on what style of worm farm you choose, the price can range from $40 for a worm cafe (the tiered worm farms) to $350 for a ‘hungry bin’, which is the size of a wheelie bin (I’ve got two of these and they are totally worth the investment!).
Now for the worms. No you can’t just use earthworms from your garden, worms used in a worm farm are a special type (red wriggler or tiger worms) – which consume large amounts of food and like to live close to the top of the soil. Unless you’ve got a friend with a worm farm who is willing to give you a few handfuls, you’ll need to spend some money for the worms to get you started. Worms can be quite expensive from the hardware chains, and often come as worm ‘eggs’ rather than live worms. I bought mine from a local gardener off Gumtree. The more worms you buy the quicker your worm farm kicks into gear, but I’d recommend at least 1,000 to get you started.
Here are some of my 5 hot tips to foster happy, blissful worms.
1. Location, Location, Location
The biggest single failure for worm farms is not choosing the right site for them. If you get this right, everything else is easy. Worms don’t like it too hot or too cold. The ideal location is indoors – in a shed or laundry. Otherwise, in the shadiest spot in your garden, with no direct sun – it’s great for those spots where nothing else will grow. We have ours under a deciduous tree next to the house which lets in some light in winter but is sheltered from any direct sun in summer.
Just like with a good compost bin, a worm farm is all about a balance of greens to browns. In other words, a balance of greens: nitrogen-rich materials ( all your household food scraps) and browns: carbon-rich materials (cardboard, newspaper, leaves).
Line your compost caddy with newspaper, which as a bonus, this helps to keep your caddy clean. When adding kitchen scraps, regularly throw in toilet rolls, paper bags and other bits of cardboard as they are produced over the week. You can also add handfuls of autumn leaves if you don’t have cardboard.
3. Not too wet, not too dry
Worms are like goldilocks, they want their moisture levels to be just right. Too wet and they might think that they are drowning and try to escape. A few thousand worms on the lid trying to escape is not a pretty sight and something you won’t forget easily! If you get the basic recipe right then you shouldn’t need to add any extra water – and no I do not recommend pouring buckets of water through your worm farm as you’ll sometimes see incorrectly recommended. A well-balanced mix of materials will not require you to add any additional water.
Being an enclosed system, the biggest risks to worms is drowning and too much moisture. Always leave the worm farm’s tap open with a bucket under it so that the liquid is continuously dripping out and the worm farm doesn’t flood. Adding browns also helps to counteract excess moisture generated through decomposing veggies.
Only getting a little bit of liquid out of your worm farm is the sign of a balanced worm farm.
4. Keep me warm but not too hot
Ensure that you have a worm blanket just inside the lid as this helps to buffer extreme temperature changes. Good free worm blankets are hessian bags, thick damp newspaper or pizza boxes, or even those squares of wool people often get in home-delivered meals.
- In winter, if your area is prone to snow and freezing, cover the entire farm with some old carpet – we don’t need to do this where we are as winters are quite mild and rarely dip below zero.
- In summer, on scorching 35+ degree celcius days, we freeze their food. Or you can freeze bottles of water or ice packs and leave them inside the lid just below the worm blanket.
5. Feed me right
- When your worms are just settling in, you may like to puree their food to help them get through it more quickly. Once they have adjusted to their environment (usually in 2-4 weeks) you won’t have to do this again.
- Feed your worms fruit or veggie scraps from the kitchen. I find that their favourite foods are watermelon and rockmelon rinds and coffee grounds. You can add food daily, or being time-poor, we tend to empty our caddy twice a week.
- A little bit of bread or cooked grains (rice, beans) that have gone off are fine, but don’t overload it.
- Coffee grounds and eggshells are all wonderful amendments
- Add cardboard (preferably matte, not glossy) such as cardboard boxes and toilet rolls
- What about citrus peel, onion and tomatoes? Once your worm farm is established yes you can add normal household amounts to the worm farm. You’ll notice that the worms avoid them but there are still other critters in the farm helping to break these down, and once broken down you worms will consume them. You’ll find they will disappear from your worm farm, but take a little longer.
- No dairy, cooked meals or meat
- Don’t feed too much food all at once – if your worms are overloaded with food, this creates acidic conditions, smells and attracts flies. Note that once they settle in, your worms will build up their numbers and become hugely efficient processors of food. When they’re on a roll, a standard worm farm should be able to process all your family’s food scraps with ease. In fact, all of our household’s food scraps go into our worm farms and we need to source more through Sharewasters (around 10 different local households drop off their waste to me on an ad hoc basis).
- Excessive amounts of tomatoes, citrus or onion – if you’ve got a glut of mandarins or oranges, or if you’re making a bulk amount of passata and have lots of tomato skins, leave these for the compost. Otherwise the small amounts consumed by a regular household are fine to add to the worm farm.
- Don’t put in any large garden prunings or large volumes of garden materials as they’re too bulky and aren’t nutrient rich enough for your worms (they should go into your compost instead).
Just remember: the quality of your worm castings will depend on what you feed your worms. If you are eating a good balance of fruit & veg, you will then be giving them a good balance of scraps from the kitchen -> your worm castings will also be well-balanced in nutrients. A great incentive to eat a diversity of fruit and vegetables 🙂
Add mixed kitchen scraps and cardboard to your worm farm
You should find that they disappear in a week or so. Your worms will become more efficient processors over time!
BONUS TIP!! EGGSHELLS
This is my secret ingredient for happy worms.
Don’t spend any money on those ‘worm farm conditioners’ that are marketed in hardware chains – we don’t believe in buying food or amendments for my worm farm. Don’t forget that we keep worms to process our waste not to support the creation of more waste!
Eggshells are packed with calcium and they help to counteract the acidity from kitchen scraps. The most effective way to use them is to keep a jar of eggshells in the fridge. Once the jar is full, puree the shells to a paste with a little water in a blender and then add them to your worm farm. You can also crush the eggshells with your hands, but this will take longer to break down. By adding eggshells regularly, you will never need to buy any fancy ‘worm farm conditioners’. As a bonus, it gives plants a boost of calcium, which prevents blossom end rot on veggies such as tomatoes and capsicum.