Ballarat Botanical Gardens trials sustainable gardening alternatives

City of Ballarat horticultural staff have been trialling a range of sustainable gardening alternatives at the Ballarat Botanical Gardens this year.  
 
For the first time, horticultural staff have trialled green manure crops in the garden’s famous dahlia garden beds, located on the dahlia lawn south of the conservatory. Green manure crops are grown specifically to be dug back into the soil. Not only does this practice increase nutrients in the soil, but it also strengthens the soil structure and promotes soil fertility.  

Usually, the dahlia garden beds are rested over winter — horticultural staff collect the dahlia tubers and store them during the colder months, replanting them in October/ November. However, growing a mix of green manure crops in the garden beds over winter, which are dug back into the garden, draws nitrogen out of the air and ‘fixes’ it onto the roots of the plant, making it available for the dahlias when they are re-planted.  

The Ballarat Botanical Gardens have more than 120 species of dahlia, which are about to be replanted. A major drawcard for tourism, the gardens have a rich history with the exotic flower species — dahlias have been recorded in the Ballarat Botanic Gardens as early as 1902.  
 
City of Ballarat horticultural staff have also trialled digging leaves from the garden’s oak trees into the soil under trees and into garden beds. Oak leaves are a great source of nutrients for the plants and for soil health — oak leaves help hold water in the soil, which is helpful in terms of drought-prevention.  
 
In the past, leaves from the garden’s oak trees have been turned into compost — as is all green waste from the gardens. However, this trial cuts out the compost process. The oak leaves are collected and then directly embedded in the soil.  
 
Horticultural staff will assess the success of the oak leaves trial next winter by examining the organic matter present in the soil. If it is successful, the trial may be rolled out more broadly across City of Ballarat gardens.  
 
These trial projects are in line with goal one of the Council Plan 2021-2025 — an environmentally sustainable future. The City of Ballarat is working to adopt more sustainable practices in core business and operations to preserve the health of the environment, while also seeking to leave it in a better condition than it was found.  
 
City of Ballarat Mayor, Cr Des Hudson, said it was great to see horticultural staff trialling innovative, sustainable gardening techniques at the Ballarat Botanical Gardens.  
 
“Our gardening teams do a fantastic job of not only making our city look great, but doing so in ways that promote sustainability and the health of the natural environment.”  
 
“I’m looking forward to seeing the garden’s colourful range of dahlias in bloom this summer.”  
 
For more information about the Ballarat Botanical Garden’s plant collection, visit the website.