The school first celebrated the internationally recognised day 117 years ago, in 1892.
Several native trees were planted in the "first step" of creating a garden area for outdoor activities, teacher Leslee McDonald said.
Pupils who were involved in the school's environmental group were supported by parents and community members in the planting.
Liam McLister was proud to be planting native trees which he said would "represent this as a nice environmental school".
Today is officially Arbor Day and World Environment Day.