How to create an in-ground worm farm

[Nham]

Difficulty: Beginner

In-ground worm farms turn food waste into rich organic fertiliser that your garden will love. They’re low-maintenance, blend into your garden and you can use pots you already own.

Getting started is easy. You can build and install your first worm farm in around one hour anywhere in the garden or even in a raised garden bed.

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Steps

Step 1

Decide on the pot you want to use. Now attach the hole saw (32-38mm) to your cordless drill. Working on a stable surface, drill into the pot to create openings on each side. For a 4L square pot, make four 38mm openings on each side and openings on the bottom, and skip Step 2. For a 5L round pot, create a similar number of openings around the pot and a single opening on the bottom as shown in the next step.

As the worms decompose food scraps, all the nutrients will drain through these openings into your garden. Don’t worry about the compost worms escaping into the garden. These species are veracious eaters and will not survive long without a steady supply of food scraps. These openings will also allow garden worms to enter your farm once it becomes established.

              

Step 2

Using a jigsaw, cut 3–4cm from the bottom of the pot to remove the bottom. Be careful as the plastic may crack due to the vibrations from the jigsaw. If you have a pot with drainage holes at the bottom, guide the jigsaw through this opening and around the pot to remove the bottom.

      

Step 3

Select a spot in your garden that is easy to access or an area next to established plants. Using a shovel, dig a hole large enough for your pot. Place the worm farm into position and refill the hole with soil.

        

Step 4

Wearing gloves, transfer a layer of worms into the pot. To get started, use around one third of the Worms Booster pack to create a 5cm layer of worms. One box can create three worm farms in 5L pots.

  

Step 5

Add food scraps into the pot next and 2 litres of water to keep it moist. Don’t overfill with food scraps and leave space at least 10cm from the top.

Step 6

Cut cardboard pieces to size and immerse in water for about 15 minutes. You can also use damp newspaper. Put 2–3 layers of soaked cardboard or newspaper on top of the food scraps.

    

Step 7

To cover the entire farm, use a terracotta or plastic saucer, or the offcut from the bottom of your pot. Place a garden feature or potted plant on top to keep it in place. Covering the farm keeps it moist and prevents other animals from getting in.

      

Step 8

Add 2 litres of water every couple of days to keep the farm moist. Your worms will begin to reproduce, and you can start a farm in another area of the garden or in a raised garden bed after 2–6 months. Repeat the process of taking one third of the worms to start another farm.

  

Materials

• 3–5L plastic pots 
• Terracotta or plastic saucer (or use offcut from plastic pot) 
• Worms Organic Booster Box 
• Cardboard or newspaper 

Tools

• Cordless drill 
• Craftright 16 piece holesaw set 
• Jigsaw with 10-14TPI blade 
• Shovel 
• Gardening gloves 
• Scissors 
• Bucket 

Images

[StevieB]

Thanks for sharing a simple way we can be kind to the environment and nourish our gardens @Nham.

Look forward to seeing updates from members who have followed your guide and given this a go themselves.

Stevie

[Aitchee]

I have 2 small courtyards, can I move these to different areas? 

Can I use the castings from these?

[MitchellMc]

Welcome to the Bunnings Workshop community @Aitchee. It's brilliant to have you join us, and many thanks for your question about this wonderful project.

Let me mention @Nham, so they are alerted to your questions.

If you have two small courtyards, I suspect it would be best to create two worm farms instead of trying to move them around. Regarding the castings, there's no harvestable layer where the castings will collect for easy removal, as seen on units like the Tumbleweed Worm Cafe that separate castings and worm wee. However, after some use, the castings will likely build up to a level where you can remove them and distribute them as fertiliser.

Please let us know if you have further questions.

Mitchell

[Nham]

Hi @Aitchee ,

Thanks for msg. Yes, you can; we move them around the garden every six months or so. The castings would be distributed all around the underground farm and be hard to separate. @MitchellMc suggested the worm cafe, where there are layers in which you can easily find the castings. I hope this helps. 

[ozziozzi]

Just wondered if it is a good idea to build garden bed up against a garden shed as seen in your pictures. I have seen metal sheeting corrode when exposed to wet soil. Scraps of pvc pipe also make good worm farms in garden beds.

[MitchellMc]

Welcome to the Bunnings Workshop community @ozziozzi. It's great to have you join us, and many thanks for jumping into the discussion.

I trust @Nham will be able to tell us whether they've had any issues with the soil built up to the shed. Typically, it's best to have sheet steel elevated above ground level; if there is an option not to have soil against it, that would be the best course of action.

Great tip about using PVC for worm farms. Do you have any examples of ones you've created to show the community?

Mitchell