Free-range worm farming

Are your worms in a factory, or free-range?

I’ll let you in on a little compost secret. A well set up cool composting bin and a worm-farm are pretty indistinguishable.

Scandalous, I know, but here’s the reason why.


Good compost is made with a good balanced blend of materials (if you have missed it you can read up on our favourite topic at the YIMBY website).

The amazing thing is, the ideal compost recipe is pretty much the right one for any compost we are making, be it hot bays, cool bins or worm farms, the main difference is just quantity.


Hot compost requires about 70+kg per week of the ideal compost recipe. But, if we put a smaller volume of that same recipe in a compost bin (most Gedye-style bins hold 150-220 litres) or a worm farm (usually smaller again), adding smaller quantities each week, it won’t get the microbial momentum to heat up, but it will break down, just slower, and those cooler conditions will actually be perfect for worms to colonise and breed up in crazy numbers.


So, a well-fed Geddy-style cool compost bin should actually be teeming with worms, and we should see them every time we take the lid off.


One of the great advantages of worm farming in a compost bin over a more traditional worm farm/worm ‘factory’ is the open bottom of the bin, meaning we don’t have a captive workforce.

The worms are there because the conditions are great for them, but they are free-range and can come and go as they please.


It is in our interest to keep conditions nice for the worms; moist and well-fed, with the right balance of rich ingredients and roughage, but if we skimp on the water for a bit over summer, or go away on holidays and don’t feed them for a few weeks, the worms have an escape route to the soil below, and we are less likely to have 10,000 wormy souls on our guilty conscience.


Do we need to add the worms? In most cases, no, they will make their way through the soil and up through the bin to find the perfect meal we have left for them.

If we don’t see worms in our cool compost bin after a few weeks we might ask a composting or worm farming neighbour if we can get a starter colony to get things going, but make sure the recipe is right first, it is more likely to be the problem than a total lack of worms in the neighbourhood (unless someone has been spraying in the area).


It is recommended to cover the bottom of a Gedye-style bin with 5mm rodent mesh to stop any furry invaders from eating the worm’s food, and that will give us more freedom to add a good range of kitchen scraps to our bin/worm palace.


Is your compost bin a favourite worm hang-out spot?


– Joel Meadows works with *Yes In My Back Yard, (YIMBY), a community-scale composting initiative in Castlemaine and surrounds. Send questions or comments to hello@yimbycompost.com, or to book in for a compost workshop!