Jun 18

DIY Worm Farm Bin

To be honest, I am actually quite proud of this re-purposing DIY. As far as what I have built from bits laying around the backyard, so far this is the upcycling piece de resistance. And I mean who doesn’t love a system which is low maintenance, high output. Worms are incredibly self sufficient and with the right home to live in they will do some wonderful things for your organic waste. They are pretty well the current kings of degrading organic matter and turning it into nutrient rich, moisture retaining, gardeners’ gold. If you haven’t come across worm castings yet, you have a whole world of naturally produced organic nutrients ready to delve into.

To learn more about home composting and some DIY projects to get your home compost system up and running check out:

  1. Bokashi Composting for the Backyard Gardener
  2. DIY Bokashi Bucket
  3. Building a Re-purposed/Upcycled Compost Pit
  4. DIY Composting for the Backyard Gardener

Why Worms?

Worms are incredibly versatile, they can adapt too many environments as long as the moisture and organic matter is at a high level. This is due to the biomass creating heat within the surrounding area as it decomposes due to other various natural processes, the organic matter maintaining a high level of moisture retention while facilitating permeability and the porosity allowing an oxygen rich environment. Earthworms were referred to as ‘Natures Ploughs’ by Charles Darwin due to their ability to mix organic matter through soil layers (1). Large proportions of the soils they work through pass through the gut of worms creating a nutrient rich by-product known as worm castings. Now a big thing to remember here is that the microbial activity is actually releasing the nutrients, however, the soil microbes are the worms main source of nutrition, they are dissolving the organic matter and inoculating it with an increased level of microorganisms contained within the worms gut which increases the amount of bio-available nutrients for plants (2). They also produce a secondary source of microbial and nutrient rich by-product in the way of ‘worm tea’, which can be filtered out by pouring an excess of water through the system. Now here is the awesome thing about worms, in an ideal environment they eat up to half of their weight in organic matter per day! You read that correctly, half their weight! So if you have 2kg of worms they will eat up to 1kg of organic matter every day. Incredible if you ask me and an absolute waste saver for kitchen and garden waste.

How to Build a Worm Farm Bin

For this upcycling project I really wanted to focus on using the materials I had lying around my house. It was something that took quite a bit of time in the thought process off how the design would work effectively and once that was decided, it was rather straight forward. Enjoy building a home for your new waste reducing friends!


  • 120L Upright Bin (I used an old spill kit bin that had a broken lid and wasn’t fit for use on the job site anymore)
  • 20L Rectangular Upright Bin (I upgraded the buckets I use for my nutrient ferments so used one of the old bins)
  • Front Lid (I used the top of an old ICB which had been used for the Greens Bubbler water storage. The main requirement is you need to easily fit your arm in and scrape out worm medium)
  • Spigot (I used a spare one laying around from the Bokashi Bucket builds)
  • Shade Sail
  • Gravel (I used 2.5 shovels from gravel around the house)
  • 7mm Bolt and Nut (anything above 5mm would work really, this is just what I had an excess of in the build cupboard)
  • Drill
  • Grinder


  • While they are incredibly hardy, they are still a living system which requires certain parameters to exist within.
  • They require a moist soil environment.
  • They require an aerated environment.
  • They require frequent plant matter.
  • They enjoy temperatures between 8C-25C (4).
  • They enjoy a PH around neutral.
  • They do not like sun or light at all.


20L bucket insert:

  1. Measure from the base of bin 17cm along and mark a line. Repeat around the bucket.
  2. Saw along the line and keep the base.
  3. Drill holes in an even pattern through the top and sides. (Try keep at least 1-2cm between the holes to keep rigidity) 

120L Bin:

  1. At the front of the bin measure 6cm above the base and mark a line in the centre
  2. Drill a hole with a width of the spigot insert
  3. Insert spigot and tighten until rubber O-ring deforms
  4. Measure 19cm above the base of the bin and mark a line
  5. Take your preferred lid and mark the measurements onto the bin
  6. Cut a hole in the front of the bin allowing enough room around the edges for the bolts to have 2.5cm from the edge of the hole
  7. Lay the lid on top of the hole and drill holes with a width of the preferred bolt through the lid and bin the circumference of the lid. Ensure the lid and bin remains flush to ensure the holes meet when the bolts go in.
  8. Secure the lid to the bin with the bolt and nut
  9. Place the 20L bucket insert into the base of the 120L bin
  10. Fill the remaining void space with gravel, flush with the top of the 20L bin insert
  11. Lay a double layer of shade sail over the gravel and 20L bin insert and there you have it your very own worm bin ready for its new occupants and to start reducing bulk organic waste!

To learn more about home composting and some DIY projects to get your home compost system up and running check out:

  1. Bokashi Composting for the Backyard Gardener
  2. DIY Bokashi Bucket
  3. Building a Re-purposed/Upcycled Compost Pit
  4. DIY Composting for the Backyard Gardener


  1. Earthwormsoc.org.uk. (2018). Earthworm functions | Earthworm Society of Britain. [online] Available at: https://www.earthwormsoc.org.uk/earthworm-function [Accessed 18 Jun. 2018].
  2. Nrcs.usda.gov. (2018). Earthworms | NRCS Soils. [online] Available at: https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053863 [Accessed 18 Jun. 2018].
  3. Worm Composting Headquarters. (2018). Feeding Your Worms. [online] Available at: https://wormcompostinghq.com/feeding-your-worms [Accessed 18 Jun. 2018].
  4. Working-worms.com. (2018). Creating the Right Environment for Your Worms. [online] Available at: http://working-worms.com/creating-the-right-environment-for-your-worms/ [Accessed 18 Jun. 2018].

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