Compost: Food Waste Turned Into More Food

In the continuing war on waste, at a household level by far the most effective strategy I have for reducing our municipal garbage output is composting. I have a very simple and comprehensive composting system.

Three large compost bins. One is filled and has been spending several months quietly composting away. One is nearly full, and one is waiting to be filled.

These bins are recycled plastic and made in Australia. They are the simplest type of compost bin - they have no base, are placed directly on the soil, they have a hinged lid. You don't need to buy compost bins - you can use any old lidded bin of any size, cut out the base and away you go. Now these bins won't make your classic turned, hot compost. They are too small to heat up properly. To make a hot compost that kills pathogens and weed seeds you need a heap that is made all at once and is at least 1 cubic metre (35 cubic feet) in size. This is generally not practical in a small suburban garden. My plastic bins are not compost bins so much as large worm farms. They produce what is called 'cold compost' but is actually pretty much worm castings, and the process takes at least a year in our temperate cool climate. If you live somewhere warmer than Tasmania the process will go quicker, and if you have snow in the winter, it will take longer.

There is no secret or complicated method to producing cold compost. You start with a bucket full of kitchen scraps on the bottom of the bin, and add some compost worms (these are the worms you buy for your worm farm. Or ask a friend with a worm farm or compost. If you live in Launceston, ask me). You will need a double handful of worm-filled compost to start. Then add all your kitchen scraps, soft weeds, autumn leaves and vegie garden prunings. Anything that isn't actually sticks can go in. Sticks take longer to break down. I throw in all my kitchen waste, even the things that you aren't supposed to put in compost bins and worm farms, like meat, bones, dairy, onions and citrus skins. The worms in my bins have never seemed to care. Mind you, I don't have rodents or a dog that digs, so I know that what goes into the bin stays in the bin. Other things I put in the compost: hair, dust and dog hair from the dust pan, a small amount of fire ash, paper towel, natural fibres of any kind, tissues that haven't been used for anything nasty. Cold compost will not kill pathogens, so I don't put anything in it that will spread germs, like cat or dog poop, or snotty tissues. Tissues I flush down the toilet. Guinea pig and rabbit poop is fine though, and their bedding, and the newspaper from the bottom of the budgie cage. Another thing cold compost will not do is kill seeds, so do not throw in seeding weeds, or plants like ivy which will cheerfully resprout under any condition whatsoever.. this also means that you will have hundreds of tomato, pumpkin, zucchini and cucumber seedlings popping up when you spread the compost in the garden. This may be a good or bad thing depending on your perspective. I do admit it is very difficult to be hardhearted and hoe all of these baby plants back into the soil.

After a year or so the compost looks like this:

The only identifiable ingredient is eggshells, which is kind of bad news for when I get chickens, as chickens who peck at eggshells can become egg eaters. From now on I will be drying and grinding up the eggshells, and saving them as a chicken feed calcium supplement for my (as yet hypothetical) chickens. Otherwise the compost looks exactly like potting mix, but has more heft to it. It is wonderful, magical stuff for the garden. It adds nutrients, but also adds organic matter to the soil, helping it to become better draining and making it a more hospitable place for plants to grow.

Things to remember - site the bins in the shade so you won't kill the worms. Keep the compost damp in the summer. Worms like alkaline, so add a little fireplace ash or garden lime occasionally. If a cloud of tiny flies fly out when you open the lid, add another handful of lime and some garden soil. You will sometimes see an explosion of tiny white wriggly worms in the bin. Do not panic. They are the baby worms, and will grow up to do important composting work like their parents, so feed them well.

For further reading, here is a list of 100 Things You Can Compost.

There are so many different ways to compost. How do you do it?


Hazel said…
I'm a slightly obsessive composter and have composted pretty much everything possible- old clothes, tatty tea towels, even a straw Ali Baba laundry basket once. I do avoid putting anything on the heaps that rodents might like as we back onto fields and have chickens and the rats really don't need any more encouragement.
I have 2 black compost bins at the moment but I'm pestering my husband to build me 3 compost bays out of pallets so I can turn the compost and speed it up a bit. My son made me a leaf mould bin the other day so I've great hopes for next year! I'd like to make to make my own potting compost. Well, realistically, maybe the year after that...
I also have a wormery (great for when it's raining and you can't face walking to the compost heaps) and 2 bokashi bins. I'd got out of the habit of using these and put stuff I didn't want to put straight on my heaps in our council collection bin but I'm trying to get them up and running again as it seems silly to send stuff away and then buy in bagged compost. The inoculated bran is expensive so I ferment newspaper in whey and molasses and that works great.

Next plan is to compost our dog poo in a homemade waste digester using the bokashi liquid as an activator. I've done it before with a plastic dustbin and it was successful but with two big dogs it filled up too quickly so I'd need two. I'd site them by fruit trees to absorb the nutrients without endangering health :-)
Anonymous said…
I like to think my worms escaped when I forgot about them. Better then thinking they died.

I have kept my composting brochures from the council though, as when my life slows down, I will start my worm farm again.

We've reduced a lot of our waste but you're right, much that goes in is food off cuts. So composting would cut our bin by about half.
Fernglade Farm said…
Hi Jo,

That is some quality looking compost. Years ago, I chucked a similar setup in the middle of a vegetable bed. Like yours the bin had no bottom so all of the worm tea juices oozed into the vegetable bed and fed the vegetables. Composting is like the ultimate action in the war on waste.


Treaders said…
I am so jealous (how weird are we). I can't wait to retire when I will have more time for this stuff. I was actually looking up wormeries on Amazon the other day! I remember a few years ago when my ex husband asked what I would like for my birthday and I said a composter - he just laughed and said THAT was never going to happen. I mean heck, I would have appreciated that much more than a perfume gift set. Are we weird or are they? Anna
Fernglade Farm said…
Hi Jo,

Didn't really answer your question:
- 3,000L worm farm - Takes all black and grey water (and anything the dogs and chickens don't want to eat)
- Chickens - Consume any edible kitchen scraps
- Dogs - They eat anything really. It's all a bit dirty really...
- Garden beds - I chuck cuttings back into the garden beds
- Brazier - Most paper is burned and the ashes spread through the orchard
- Burn offs - Most forest litter which falls in heavy winds is collected and burnt (there is a lot of it). The ashes are very useful in the orchard.

Plus I take other peoples organic matter, although they may call it waste. The coffee ground situation is working quite nicely. :-)!

Oh yeah, just for your readers info: Worm eggs are viable for up to 2 years. And worms travel deeper into the cooler soil in hot weather.


Meg said…
We have three ways of making sure that no kitchen scraps leave our place. We have two rotating compost bins (they have their advantages and disadvantages ... I once flipped a snake out from under one when I was turning it!), a worm farm and our dog...who, being a Labrador, eats just about anything but especially loves meat scraps (which I don't put in my compost). Dog hair, from said Labby, goes in the compost bins too. Recently, a neighbour traded her old unused worm farm for a basket of fresh veg from our garden so soon we will have two worm farms at our place. Bargain! Meg:)
Jo said…
Hazel, wow, that's all the different types of composting in one yard! Extraordinary! One of my friends has a commercial dog poo composter, but it is basically what you have suggested - a lidded bin set into the soil. I have to admit that currently I throw dog poo into the giant waste pile at the back of my garden that will one day be corralled by a retaining wall to become a fruit tree garden bed.. at that point, when I don't have a big pile of garden waste anymore, I will have to rethink my dog poo waste disposal method. I think your plan sounds grand!

Chris, wow, 3000l worm farm? You win! Is that a commercial set up, or something you made yourself? It looks like you have really thought through all your organic waste options and have them all covered. I salute you as a Very Useful Human!

Anna, I don't think we are weird. Perfume gift sets don't make the world more interesting, but worm farms are fascinating AND useful! Honestly, if you get a big plastic compost bin, and just put worms and compost in, it will take no time out of your daily routine at all, except for taking the compost out to the bin. Worm farms are, in my opinion, too small to be really useful, and being small, they dry out really easily in warm weather, and freeze in the cold. In a big plastic compost bin the worms keep cool in summer (in the shade) and burrow down into the earth to hibernate during your cold winter - they are very self-sufficient if given the right conditions. Just do it!

Lucinda, I am sure your worms went on a trip to a lovely farm where they lived out the rest of their lives in peace and happiness :)

Again, if you are thinking about composting, just get a big bin and chuck worms and compost in. It will pretty much look after itself when you go away as well, just get on with making nice compost. And the worms won't, er, retire, like they do in a small compost bin :) xx

Meg, that was a good snake story! Snake compost! I hear you on the dog solution to waste.. ours will eat anything as well. Except green beans.
GretchenJoanna said…
Thank you for the helpful and interesting lesson!! I really would like to use my kitchen and yard waste myself - have been hoping to get worm bins started...

When we had chickens we used to give them eggshells to return those minerals to them, but only after baking them in the oven. Our mentors had taught us that. We also gave them supplemental mineral grit - but all my knowledge of chickens is probably way out of date!
Jo said…
Gretchen Joanna, that information is very up-to-date - wash the eggshells, bake them, then grind them up into shell grit. That is my plan :)

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