It's been seven years since University of Canterbury's Student Volunteer Army was formed, and on Saturday it was out in full force.
The students helped clean up Christchurch's Godley Head - a Department of Conservation reserve and historic WWII site in the Port Hills.
More than 1000 students were out of bed early on Saturday.
Student Volunteer Army President Josh Blackmore says, "We've found that they're quite engaged in it. If you provide the tools and the opportunity, then they're very willing to get out there and help."
The students worked with Department of Conservation (DoC) rangers in 20 different groups planting trees, chipping paint and fixing fence lines.
DoC ranger Alan McDonald says the department has worked with the volunteer army for a number of years.
"Today is just a great example of the value of volunteering."
Social entrepreneur Sam Johnson founded the Student Volunteer Army in response to the Christchurch earthquakes. His work saw him named Young New Zealander of the Year in 2012, and his legacy remains at the university.
"The challenge after that was, hey, how do we do this without a big need from a natural disaster?" Mr Blackmore says. "So for the last seven years we've been figuring that out. But at the moment we're hitting a really good spot."
The student army has had a record number of students sign up this year.
With more than 2000 members already, some who turned up on Saturday haven't yet registered.
The group is expecting about 3000 members by the end of the year. That's about a quarter of the university.