Mandarins in Greenlane and feijoas in Glen Eden; if you only knew where to look you would find plenty of produce going begging in Auckland City.

Now an initiative started by an ecologically minded local is encouraging New Zealanders to use food resources that would otherwise go to waste.

Three months ago Otahuhu resident Michael Brenndorfer set up the New Zealand fruit and food share map after reading about similar projects in the United States.

Using Googlemaps, he created an interactive map showing people where they could find food growing in the city and invited them to add spots they knew of. There are about 40 plants marked on the map, with notes about harvest times and locations.

Mr Brenndorfer created a Facebook group to advertise the concept and it didn't take long for other towns and cities to catch on. Now there are listings ranging from wild fennel in Greymouth to blackberries in Dunedin.

Mr Brenndorfer describes himself as being concerned about sustainability and eco issues and says there's a lot of food available within the city that gets wasted.

He says he would like to get to the point where he is approaching people with plentiful fruit trees on their property to see if they would be willing to share the spoils.

"The map is kind of running itself but there is definitely scope for expanding, too.

"My dream would be to do a flyer-drop asking people to join the network and to start having a regular banquet using foraged foods."

Mr Brenndorfer founded the University of Auckland's Sustainability Network and is currently involved in setting up an organic food co-op for students and an on-site veggie garden. He says it was a slow and painful process to get permission but the group have been offered a spot near the business school.

He says he is interested in ways people can grow and forage their own food and the garden will be a teaching tool and an example of urban agriculture in the city.

On Thursdays at the University of Auckland, Mr Brenndorfer serves a vegan lunch to a diverse group of about 180 students.

Huge cauldrons of food are prepared in a catering caravan at Mr Brenndorfer's home and the sugar cane plates and corn-starch plates go straight onto his compost heap.

Every square metre of the Otahuhu property is dedicated to vegetable patches, composting systems and a couple of greenhouses. Standing knee-deep in kale and broccoli, Mr Brenndorfer says his household hasn't had to buy vegetables for more than two years.

"If people are serious about reducing climate change and our emissions, the main area we need to look at is our diet and a vegetarian or vegan diet has the lowest carbon footprint."

* NZ fruit and food share map