It's not the most dangerous assignment they'll ever have but hundreds of trainee officers are hard at it until Sunday shoveling and hammering in 25 sites around Canberra as part of their training in the Australian military.
The idea of Exercise Weary Dunlop is to instill a sense of community into them - both their own community but also as part of the wider community which is Australia.
"Putting others before yourself," is the way Major Tobias Raimondo who is in charge puts it as the trainee officers create a garden in the grounds of Canberra College in Phillip.
I need to trust that the leaders that we are growing, when they go out to war or whatever it is, are doing the right thing.Major Tobias Raimondo
He acknowledges that the primary purpose of the military is to be ready to fight but he says this kind of exercise helps people rely on each other in all kinds of situations, including war.
"I need to trust that the leaders that we are growing, when they go out to war or whatever it is, are doing the right thing," he said.
The trainees at the Australian Defence Force Academy in Canberra are between 18 and 21 years of age. They are combining military service with degrees - and a lot of gardening and weeding over the coming days.
Nineteen-year-old Emily Kolokotas from Tamworth signed up because she wanted to travel and to "learn how to lead".
She was ambitious in school. "I was always that student who was eager to get involved in things. I just wanted to do something bigger and different."
She is now a Midshipman - the first step on the ladder to being a full naval officer.
She feels she's grown since signing up, particularly "my confidence and sense of self".
"I feel as though I'm doing something for my country and I feel as though I am doing something important," she said.
The sense of service is echoed by Officer Cadet Lily Attwood from Batemans Bay.
She joined the air force because she wants to be an aeronautical engineer "so it made sense to work with the best aerospace technology there is in Australia".
She is the first in her family to join the military. "I didn't have much of a sense of what military life would be like but I thought it would be a really good opportunity to gain a skill-set and get a degree while I help out those in need," she said.
She said outsiders sometimes get the military wrong. The macho culture, for example, has gone, she said.
Women are welcomed. A quarter of the Defence Academy's trainees are female.
Major Raimondo said the training was about bringing out the character in people. "It's really difficult to train character if it's not there already. It's about their true self," he said.