February 11th, 2025Shhhhhh! the compost is cooking…

The Hepburn Shire Council is preparing to start applying the first batch of compost to its Parks and Open Spaces trial sites to measure the benefits as part of a Sustainability Victoria funded trial.

The picture above features 40 cubic metres of compost made from kerbside food and garden organics collected from townships across the Hepburn Shire.

The volume of compost produced is less than the volume of material collected because, just like spinach, organic matter dramatically reduces as it ‘cooks’.  

The first stage of composting occurs in the council’s rapid in-vessel composting units at the Creswick Transfer Station. After two weeks, the compost is taken out of the vessels and allowed to cool outdoors while it continues to mature and gets closer to being ready to be applied to plants.

Matthew Daniel of Hepburn Shire Council’s Parks and Gardens team said that much like the story Goldilocks and the Three Bears, good compost needs to “not be too hot, too cold, too wet or too dry”.

He has been closely monitoring the temperature and moisture of the maturing compost to determine when it will be ready to use. Recently, the compost was 40 degrees which is an indicator that it is almost ready to use on sites.

The temperature of the compost indicates how active the thermophilic (heat loving) bacteria are. Now that the temperature is decreasing, the team knows that the bacterial activity is slowing.

Once it reaches an ambient temperature, the compost is considered ‘optimised’ (has the right mix of microbes) and is ready to apply to plants.  

Optimised compost helps to prevent disease but also improves the structure of soil to reduce compaction and increase water retention, a bit like a vaccine does for humans.

Matthew will also test this compost to see the microscopic organisms (like bacteria, microbes, fungi, protozoa) present, before putting it to use.  

Matthew also demonstrated the compost tea making kit he is putting together. Soon he will be adding small amounts of compost to ‘brew’ up a microbe rich tea that can be sprayed around the base of trees to improve their health. 

Council staff are working hard to remove contamination at various stages, mainly by hand. However, it is very difficult to remove completely. They are still seeing some contamination (for example, plastic) ending up in the compost pile.

By far the easiest way to keep the compost clean is for residents to avoid putting any plastic (such as bags) or other rubbish in the lime-green bins.

Those keen to know more can visit the council’s Food and garden organics webpage to find out what you can and cannot put in your kitchen caddy and lime-green lidded bins. 

This story based on a Hepburn Shire Council report