Five things I’ve learned in three years of worm farm composting

urban worm farming

It’s been nearly three years since my partner ordered some worms and kickstarted our adventures in vermiculture. Since then we have kept many, many generations of worms alive and used their castings (waste) on our little container garden. Maybe a good time to share my experience with worm farming in a small Sydney apartment. 

  1. They are firmly outdoor pets. I find enough (large, creepy, crawly, and sometimes all of the above) critters indoors, that I don’t want to attract any more thanks very much. Our worm farm lives in a shady spot on our patio and teems with life, not just worms. Bokashi is a better bet if you want something to store your food scraps indoors.
  2. Worms are lower maintenance than I expected. After having a baby, I didn’t my little friends for months at a time. Did they mind? Uh no, I think they thrived on a break from scraps. The population boomed. It’s easier to overfeed than underfeed, which takes me to my next point….
  3. The capacity of a worm farm is not nearly enough for a small household’s scraps. Even when I minimise food scraps (generally don’t peel veggies, eat the leaves/stems, etc)., we have too much food scrap for one worm tower. I would suggest that a worm farm can reduce or complement organics recycling, but not bring it to zero if you are like me and prep and cook most meals at home. 
  4. Eggshells don’t really breakdown. I no longer add eggshells to my worm farm.They make a mess of the compost that comes out and make it more difficult to mix into the soil.
  5. Adding scrap paper dramatically improved the worm farm. I learned that when I add torn cardboard or scrap paper to the top tray, where the worms eat, I didn’t need to turn the mixture as often to aerate.

Worm farms are a bit messy and I don’t think there is any getting around that. They don’t smell and are low maintenance. Great if you have a bit of outdoor space (my tomatoes seem happy). However, capacity is an issue, and a worm farm can’t address the volume of food scraps that a household generates. We still need systemic change in how we handle our food scraps. Aussie farmland needs more carbon than is being returned from the cities – a regional issue, not a personal one. And a pressing once, since carbon helps soils retain moisture.

Most of my compost goes into a food scrap bin that my local council collects and sends to a small anaerobic co- digestion plant in Western Sydney. The facility produces gas which is used to generate electricity and the remaining sludge is used as fertiliser.  More and more councils are offering food scraps collection – does yours?

It should be easier to compost in Sydney

I buried a year’s worth of a stranger’s food scraps last weekend.

She’d watched the ABC’s War on Waste series last year and was spurred into action. She started collecting her food scraps for compost, persisting in spite of the challenges of living in a small apartment with no council collection.

Fanny reached out to me online, where I list myself as a drop spot on ShareWaste and another Facebook compost sharing group. I have a small garden bed and our building participates in the local council’s food scraps recycling trial. The latter of which provides us with weekly kerbside collection (supplementing the green lidded garden waste bin). I consider myself lucky to have access to resources that make it easy to compost, and share the wealth whenever I can.

She alighted from a ride sharing vehicle with her 19L bokashi bin neatly contained in one of those large IKEA carry bags. A bokashi bin is like Mary Poppins’ handbag – it can hold more than you ever thought possible. As the beneficial bacteria pre-digest the scraps, everything compresses. Occasionally draining the juice helps reduce the volume too.

It was her first time using bokashi, but the thick white layer of mould on top of the scraps told me she’d done a perfect job of fermenting the batch.

I showed her the trench in my garden bed where I’d bury the bokashi as well as the nice black compost from the last batch I myself had recently buried. The process of decomposition once the bokashi is in the ground is phenomenally quick – it took maybe two to three weeks for the last batch to disappear.

We chatted about the challenges of composting in an apartment with no outdoor space. Most cities have not prioritised the recycling of nutrients, even as farmers’ fields lose topsoil and soil carbon at an alarming rate. It’s so much more difficult than it should be to compost here.

Which is why Fanny and I are both participating in this experiment of peer-to-peer exchange. I’m not mad at it, and I’ve met the best people this way, but I don’t see this DIY model catching on with the masses. Ditto for fee-based scrap collection services. These solutions don’t reach beyond the highly motivated. I reckon the majority of people fully understand the value and purpose of composting, but they’ll still object to rate increases to fund it. Blame mental accounting and defaults. One day I hope we agree that it’s the most crazy to fund profligate use of landfill as we do now. The opportunity cost of landfill is high and, as I see it, displacing potential investment in organics recycling.

There are other barriers too. Roommates, and even family members, are part of the social infrastructure of our lives and can either help or hinder our behaviour change efforts. Fanny’s new roommate objects to the idea of composting on the grounds that the bokashi bin grosses her out. Not everyone gets as excited about white mould and landfill diversion as me. The smell of the draining juices made her think the bucket would have a pervasive daily smell (it doesn’t). The juice is smelly when draining, but this happens so infrequently it would be like complaining about walking past a dumpster, or a child whose nappy needs a change.

Given my propensity for behaviour change literature, I offered her some suggestions to bring the roommate into the fold. I recommended she not force the issue on moral grounds, but instead try a structural intervention that would create ease and provide an emotional buffer between the roommate and the bokashi bin: a benchtop receptacle for daily veg scraps. The roommate could use this instead of touching the bokashi bin directly. The benchtop collection bucket – maybe on old ice cream container – could be deposited (by Fanny) in the bokashi bin once a day. This also keeps the main bin’s contents anaerobic. Fanny brightened, “And everyone likes ice cream”.

Fanny’s roommate doesn’t need to think differently before she acts differently. Humans are not rational, we’re post-rational. We can make up stories to explain just about any behaviour. When we change our actions, our story about why we’re doing it will change too. Once she starts using the less identity-threatening benchtop bin, the roommate will become the sort of person who composts, and I predict more positive feelings about composting and bokashi will follow.

We don’t need everyone to become a card carrying environmentalist, but we do need everyone to participate in food scraps recycling. Sometimes tribal motivation is a good strategy to get us there, but it’s certainly not the only strategy.

I’ve asked Fanny to let me know how it goes.

UPDATE: She let me know that it worked!

How to keep worms happy in hot weather

Tips for keeping your worms comfortable in the heat. 


People usually think of Sydney as a sunny, happy place. It is, mostly. There is also a level of extremity that takes some getting used to. A day that begins at 35 degrees might plummet to 22 within minutes of the antarctic southerly wind belting through (laundry pegs are essential). The city itself is a concrete heat sink. New housing developments lack trees, which are sorely needed to help to pull water from ocean onto land to regulate temperature and provide shade for people and roads. No surprise then, that we’re smashing heat records, a rain storm destroyed the roof of our last apartment, and the occasional tornado rolls through town. Applying local indigenous knowledge of the seasons makes so much more sense than the imposed European framework of spring, summer, fall, and winter. We are in the ‘hot and dry’ currently. Labels aside, temps over 30 degrees are normal at least half of the year. At times it’s hotter still, with heat waves in the low 40s lasting for days. Like humans, worms don’t thrive in extreme heat. Weather above 30 degrees celsius can stress worms and even kill them.

Here are a couple of tips to manage worms in the heat:

Shade: House your little guys are in a shady spot. If you lack space, a hessian sack or an an umbrella can be repurposed to create shade – in fact it’s the perfect way to get more use out of a broken umbrella.

Balanced bedding: Add newspaper and bits of cardboard to keep their home balanced between carbon and nitrogen and nicely aerated. Toilet paper rolls, newsprint and egg cartons all work well. Make sure the bedding is overall a bit moist.

Reduced feeding: Worms don’t eat as much in the heat, so reduce the volume or pace of feedings leading up to and during a heat wave.

Make popsicles: Freezing and/or blending scraps helps your worms eat them faster and doubles as a way to cool the tray temperature. Worm popsicles!

Block ice: On scorcher days, when I don’t want to add any more food scraps, I put a bucket of ice, frozen as a block, into the feeding tray. I keep this block on hand through the summer so I’m always prepared for a heat wave. You could use any sort of container that will accommodate the expansion of water as it freezes.

A hot day here or there isn’t the end of the world, and worms are still fairly resilient creatures. My worms survived a heat wave above 40 last year when I was out of town and couldn’t give them some ice. Probably because they were already shaded, had decent bedding, and weren’t overfed in the lead up.

Compost and the city: what I’ve learned about composting in a small apartment

worm farm stacking trays
My mission is life is to get everyone composting. Recycling food scraps and organics is the habit of champions thanks to its methane reducing, carbon sequestering, topsoil enriching benefits. So why don’t more of us do it? 

Grow up, leave home, stop composting

Many of us grew up composting and fell out of the habit when we left home, thinking we needed yard space to so it. That’s more or less what I thought. In any situation where I had enough yard space I would dutifully go get a large black bin and give it a whirl, only to be knocked back by a landlord who just didn’t get it. Sound familiar?

In moving to Sydney, a yard was not in the cards. My two biggest barriers to composting were:

  1. finding a solution for composting or food scrap collection in an apartment with extremely limited outdoor space, and
  2. finding a place to drop off my scraps after collecting them.

worm farm
A guerilla worm farm spotted around Sydney.

The good news is that composting can be done in a variety of ways, including, but not limited to, traditional outdoor heap stye, worm farms, Khamba and Bokashi. I had done Bokashi for a few years back in Vancouver, so that was a natural choice. It’s ultra convenient, can be stored indoors, takes a wide variety of food and organic scraps and doesn’t smell. If I can do it, anyone can do it. More recently I got a worm farm.

The next issue was where to take the bin contents, which I’ve also been able to solve. Over the past few years, I’ve shared quite a bit on this blog about how I’ve been able to compost in an apartment without yard space or my own bin style compost. If you’re keen to start composting, but don’t know where to start or what will work, have a read through some of my previous posts that I’ve linked to below. Bokashi is an excellent system for beginners. If you choose a worm farm instead of, or as well as, Bokashi, they aren’t difficult to manage either.

Here’s a collection of my Bokashi & worm farming, and composting posts: