A multi-storey car park might not seem like the ideal location for a vegetable patch but the rooftop of one next to Melbourne's Federation Square hosts about 140 vegetable crates, rented by residents, restaurants and businesses in the CBD.

Camilo Poveda from the Pop Up Patch said the project started three years ago to make the most of an unused space.

"This is the proof that you can do that within the city, just making use of spaces that are empty or vacant and just transforming them to places to grow food," he said.

"There's no need to travel far to get what you get from here.

"We plant with the seasons and we're very lucky to have all-year-long produce out of the boxes."

The Pop Up Patch occupies the rooftop of a multi-storey car park near Melbourne's Federation Square. ( ABC News )

Bringing the backyard into the concrete jungle

The Pop Up Patch is part of a growing trend of projects bringing fresh produce into the city.

Mr Poveda said members who rent the vegetable crates sometimes came to enjoy the space, and did not have gardens of their own.

"Spaces like balconies are not big enough for them to grow their own food," he said.

"Melbourne is pretty spread out and most of the houses and stuff have their big spaces at the back to grow food.

"But people within the city [don't] really have that space so we thought it was important to give them the space to grow their own stuff."

Taking over unconventional spaces

Hives of honey bees on the roof of Federation Square in Melbourne. ( ABC News )

On top of Federation Square, a different kind of city worker is hard at it.

Ten hives house up to 300,000 bees on the building's rooftop.

Matt Lumalaso from Rooftop Honey has been tending to bees living on the city skyline for about six years.

He said it began with a backyard hive, but he and his wife saw the potential to do more.

Rooftop Honey wants to raise awareness about the importance of bees to the ecosystem. ( ABC News )

"The role that bees play in the food chain is huge and sometimes taken for granted in Australia," he said.

"At least one out of every three mouthfuls of food is the result of bee pollination. They're essential for 65 per cent of our agricultural crops' pollination.

"Without our bees, as well as native pollinators living in the area, no-one could grow any fruit down there or any food."

Mr Lumalaso said the growth of urban food production projects reflected the changing nature of the city itself.

"A lot of traditional thinking of the city was that it was somewhere people came for the day to work and went back home to their homes," he said.

"But now there are so many people living in the city.

"People want to grow their own vegetables, people want to have their little gardens and having the urban sprawl and the concrete jungle, it's pushed natural habitat out."