Thermal (or hot) composting is the most popular form of composting. I chose this method because it’s quicker than cold composting, it creates the perfect enviroment for a variety of microbes to grow in the compost, kills wedd seeds and results in a rich and alive compost for the garden.

Compost circle using scrap wire, recycled hessian bags and PVC pipe

Christiaan’s easy compost recipe:

The materials you will put into your compost will be either carbon or nitrogen rich materials. The ideal C/N ratio is roughly 30:1. That being 30 parts carbon to 1 part nitrogen.

Nitrogen materials
Food scraps (with thanks to our community food scrap donors!)
Coffee Grounds (no more than 20% of the pile)

Carbon materials
Aged wood chip (we have piles and piles of it on the farm)
Saw Dust (Courtesy of Michael O’Dell at the Ulmarra Wood Shop)

Nitrogen materials- food scraps and coffee grounds

As the compost pile starts to heat up it will go through a number of stages.

These are –

1. Mesophillic stage (moderate temperature phase)

2. Thermophillic stage (high temperature phase)

3. Cooling and curing stage (this can take a few months)

During the Mesophillic stage, bacteria predominates. These bacteria are sphere-shaped cocci or spiral-shaped spirilla. As the compost heats and rises about 40 degrees (Celsius) the thermophilic stage begins. Once the temperature reaches between 55-65 degrees it will begin to kill off pathogens and weed seeds. The temperature should then slowly return to ambient temperatures in which the cooling and curing of the compost will begin.

Moisture is also an extremely important component. Depending on who you follow, the ideal moisture levels of your compost are roughly between 55-70%. This provides the ideal environment for the microbes/ bacteria to get to work.

My first pile I used a piece of plastic piping which acted as a lung to help aerate the pile and stop it from becoming anaerobic. I layer these ingredients until my pile is at 1m high x 1m wide. This will ensure that it is big enough to heat up.

My first few attempts of making compost started in late May/ early June and I built my pile to be roughly 1m x 1m. I used a wire cage and just piled everything up in layers (nitrogen-carbon).

For whatever reason (possibly the fact that during June the temperatures dropped below 10 each night) it really struggled to reach active temperatures (Between 36 – 55 degrees).

However with a few tweaks I noticed that simplifying the ingredients that went into my second compost pile this allowed it to get to the correct temperatures.

Given I’m still learning I have tried to keep a daily temperature chart just to allow myself to understand if the pile is heating up or not and if/ when to give it a turn. It’s currently sitting at 61 degrees which is a sweet spot in the thermophilic stage so a turn is necessary in the coming week.

Here is a list of amazing Youtube videos to inspire and motivate you to start your composting journey -

No Till Growers Compost series –

https://www.youtube.com/watch?v=jamdKbk3vl8&t=687s

https://www.youtube.com/watch?v=6Ti5g-AZiTs&t=715s

The Weedy Garden –

https://www.youtube.com/watch?v=IV_kkJy3s3Q&t=661s

Soil Food Web hot compost -

https://www.youtube.com/watch?v=jErga1eP718&t=591s

Quick hot compost (Geoff Lawton)

https://www.youtube.com/watch?v=CRSm4kIG5yk&t=1928s

See ya in the garden!