How a DIY worm farm can compost food scraps, paper or a whole kangaroo

Compost worms can make quick work of food scraps and other waste Rob Walls/Alamy Worms. I’ve got a few. I split my time between a small inner-city apartment in Sydney, Australia, and a wild property that was once a farm, before it was abandoned in the 1970s, four hours to the south. They are opposites in almost every way – one thrums with the incessant noise of a big city, while the other moves to the beat of the wilderness: kookaburra choruses, deafening cicadas and, at night, powerful owl hoots and the gurgling, zombie-like calls of brushtail possums. But the one thing both properties have in common is that they each boast a cranking worm farm. The one on the farm is huge and deals with the organic waste of an entire household, while the one in the city is small enough to fit on a porch and easy to set up – suitable for anyone. Read more There’s growing evidence the big five mass extinctions never happened On the farm, I’ve continued to let nature take its course on the land and use it as a place to retreat to for peace and quiet. But below ground, it’s busy. Inside a 4000-litre tank buried on the property, there is a vast colony of worms , into which pours all my sewerage and grey water. The worms turn the sludge into nutrient-rich juice and excreted castings, which are slowly released, filtered into a series of infilled porous trenches and then out through the soils into the surrounding forest. The giant worm farm in the wilderness has a lid and it is possible to vary the worms’ diet a little from a daily fare of toilet waste and shower water by throwing in my compost and weeds, as well as the occasional kangaroo, possum or bird carcass that I find on the property. My rule of thumb is that if it was once alive, then its final resting place is the worm farm. Free newsletter Sign up to The Earth Edition Unmissable news about our planet, delivered straight to your inbox each month. Sign up to newsletter When I take off the cover and look into that black hole of decomposition, I am always stunned at how quickly whatever ends up in there disappears. A dead, 50-kilogram, male eastern grey kangaroo ( Macropus giganteus ) is barely recognisable after a week, and invisible to my torch after a month. Admittedly, the worm farm is now a multicultural ecosystem that includes frogs, spiders and fly larvae, all thriving on that nutrient-rich humidity that would do the Daintree Rainforest on Australia’s north-eastern coast proud. And yet, even after more than eight years of being a repository of all things biological – I’ve shovelled wheelbarrows full of organic material into that insatiable wormhole – its steady state seems to be no more than a quarter full. No matter how rank a dead kangaroo or maggoty bird is when I hurl it in, I have never once smelled any foul odours coming from my worm farm. This is no amateur-hour operation – the local shire council comes out every couple of years to inspect that it is officially compliant. On the day the worm farm wa