Wattle Day is a day of celebration in Australia on the first day of September each year,[1] which is the start of the Australian spring.[2] This is the time when many Acacia species (commonly called wattles in Australia), are in flower. So, people wear a sprig of the flowers and leaves to celebrate the day.
Although the national floral emblem of Australia is a particular species, named the golden wattle (Acacia pycnantha), any acacia can be worn to celebrate the day.
The day was originally intended to promote patriotism for the new nation of Australia:
"Wattle Days emerged to prominence in Australia in the early years of the federated nation. They took on some of the national and civic responsibilities for children that [the more formal] Australia Day could not." - Libby Robin[3]