It's a perfect Autumn Day to go for a walk through Melbourne's Royal Botanic Gardens with its director Tim Entwisle. Australia is a country of so many climates, but for those who have the distinction of seasons, Autumn is a glorious time of year in the garden — also known in the Kulin Nation seasons as the Wombat time of year. We ask philosophical questions about flowers; if you're a Tibetan, why do you choose now to bloom? And Jonathan discovers a new pocket of the garden: the compost yard.