Research has been conducted into the performance of two organic growing media compared to a standard mineral based medium used in rooftop gardens. The two growing media under trial contain a higher proportion of organic matter than the standard media, with a high mineral content. The testing was carried out by The University of Western Sydney to ensure independent data.

1. How does run-off water compare in quality between the organic mixes and the standard mix?
    
2. Do the organic mixes show any slumpage or shrinkage, and how does this compare to the standard mix?
   
   
3. Do the organic mixes weigh less than the standard mix, when both wet and dry?
   
   
4. How does the temperature of the supporting substrate compare under planter boxes carrying the organic mixes and the standard mix?
   
   
5. How does plant growth compare in the organic mixes, compared to the standard mix?
   
   
6. What depth of organic mix is required to give optimum results for plant growth, temperature reduction and quality of run-off water?

The final report from Assoc Prof E. Charles Morris can be found below. A brief summary of the conclusions can be found in the conference presentations below. The Hills BARK BLOWER ™ staff
would like to thank OzBreed and Atlantis Water Management for their involvement and
support in this project.

Click the links for more information on the bulk density and components of the mixes.

Presentations

Associate Professor Charles Morris
Roof top Garden Trial

Sidonie Carpenter
Green roofs Challenges and Rewards

Annie Kavanagh
Compost in the Environment

To find out more about the DECCW’s research into compost and recycled organics,
click here.