There is an entrance to the botanic garden here. The sign has fallen down, but the path is maintained.
Note. its quite steep asphalt 

https://www.google.com.au/maps/@-37.3426368,144.1476578,3a,75y,103.94h,95.4t/data=!3m6!1e1!3m4!1sVJn0_Vz2ETxWmUjqZxmFLw!2e0!7i13312!8i6656