By Sally Round of RNZ

It’s prep time in the kitchen at Evelyn Page Retirement Village in Ōrewa, north of Auckland, and another load of food scraps has just gone into the bin.

Senior lead chef Dylan Hatt sprinkles some special sawdust over the top and closes the lid.

A few kilometres away in rural Wainui, a dedicated team of Year 8 students, in masks and gloves, is collecting caddies from the classrooms and emptying the lunchtime food scraps into larger bins, tamping down the gloop to a gleeful chorus of “eew” and “yuck”.

A few more kilometres inland, a banana farmer is at his specially built “jetty” unloading dozens of wheelie bins of food scraps into a “fast feeder” which spreads the fermented waste into ditches lined with biochar.

He then covers it all with mulch and leaves it to nourish and build the soil.

This is the chain created by City to Farm, a project run by Hibiscus Coast Zero Waste (HCZW), to stop food waste going into landfill, to lower greenhouse gases and nourish local farmland.

“This is a way for everybody to participate in climate action with their food scraps, just sending them off to the farm,” HCZW trustee Betsy Kettle told RNZ’s Country Life.

City to Farm collects food scraps once a week from 25 collection points in the district, including kindergartens, cafes and restaurants, schools and the retirement village.

Partially grant-funded, it has diverted more than 350 tonnes of food scraps from landfill since it started in 2019.

The food scrap producers pay to have their scraps taken, which also helps fund the operation, Kettle said.

Betsy Kettle, one of the drivers of the City to Farm project, checks out one of the specially adapted food scrap bins at Ryman's Evelyn Page Retirement Village. Photo / RNZ, Sally Round

“We don’t call it waste. No, these are resources,” she said, lifting the lids of bins in the basement of the retirement village.

They have woody mulch and biochar in the base to help with the pickling process known as bokashi.

The bins are strapped down to make them airtight, ready for the weekly pick-up truck, which then transports the bins to the banana farm for further composting and integrating with the soil.

The City to Farm project, run by Hibiscus Coast Zero Waste, collects food scraps from 25 centres - retirement villages, schools, kindies, restaurants and cafes - to be turned into compost for soil improvement on farms nearby. Photo / RNZ, Sally Round

One of the retirement village’s residents spotted the project in the local paper, and it took on a life of its own, village manager Jill Clark said.

“There’s no extra work. It’s just so routine.

“Now that’s just what we do, because we’ve been doing it so long.”

It’s also become normal for the children at Wainui School.

“When we started it, we didn’t really know what to think of it,” Year 8 student Madison Freestone said.

“We kind of just like, did it, and we were sort of like, ‘eew’.

“But now we do it all the time, and we do find it cool. We find it fun. We learn new things all the time.”

The Year 8 student team in charge of food scrap recycling in the school vegetable garden. Arielle Oswald (left), Leah Andrell, Morgan Price, Madison Freestone Photo / RNZ, Sally Round

Madison and three other Year 8s form a dedicated team of food waste busters at the rural school.

The bokashi method doesn’t attract rodents, a particular problem with composting in a rural setting, principal Gillian Bray explained.

The fertiliser created from leftovers is feeding the school vegetable garden, as well as City to Farm.

Kettle said City to Farm provided schools with special food scrap caddies and a little stand that also took paper and hard recyclables.

She said they talked to the children about the link between food scraps and greenhouse gases when placed in a landfill, as well as the way food scraps, together with biochar, can build topsoil and create a carbon sink.

Wainui School's recycling hub where food scraps are turned into nutrient rich fertiliser Photo / RNZ, Sally Round

The Year 8 girls have taken to educating too, and they’re very strict about what can’t go in the caddies.

“Any liquids, such as yoghurt, you know, juices, that type of stuff, no whipped cream, no meat, because the meat can make maggots grow, and it’s gross.

“Yeah, and obviously no rubbish.

“So, if someone does something wrong, we remind them that they can’t put that stuff in the bin.

“And we tell them what they can and can’t put in the bin, so that they know for next time.”

Teacher Nick Wotton, who leads the project at the school, said the girls had taken the task on with gusto.

“Our goal is for our students to be more sustainable and environmentally responsible, and I think this, starting with the girls, is a way to sort of embed that in our students and in our culture as a whole.”

Scraps to soil

Phil and Jenny Grainger looking out over their growing banana farm, fuelled with food scraps Photo / RNZ, Sally Round

Down the road from Wainui School, Phil and Jenny Grainger are hosting lunch at a large table.

Big bunches of bananas decorate their off-grid home from which wafts a delicious aroma.

Jenny has made a banana curry from bananas grown out of the once-poor soil, which has been nourished by six years of food scraps.

“When we first came here, there was hardly a worm on the place,” Jenny said.

The land was also dry and hydrophobic, repelling water.

The couple, former dairy and kiwifruit farmers, took on the task of taking in the food scraps to see how soil could benefit and “to sequester carbon”, Phil said.

They experimented with banana swales, digging ditches and building up banks for the plants with biochar and the fermented scraps, topped with mulch.

Rainwater and organic matter were then able to infiltrate the clay soil.

They also developed systems to make food scrap application more efficient and not so messy, and now apply the scraps once a month using a fast feeder and orchard tractor.

“Initially, it was having a car trailer trying to unload these wheelie bins and tipping and mud and stuff, and it was disgusting and terrible,” Phil said.

The Graingers have planted more and more banana plants as the food scraps initiative has grown, and they’ve had the soil tested and learnt more about growing the fruit.

Other challenges emerged on-farm, including rats and flies, but surprisingly, odours were minimal, likely due to the bokashi fermentation process, which prevented putrefaction, Kettle said.

“Although the work was messy, the impact was undeniable.”

The Graingers are now transitioning into producing bananas commercially.

Kettle said her husband did some sums and they reckoned half of Auckland’s food scraps could be diverted from landfill on to 400 hectares of farmland.

They’d like more farmers and communities to be involved.

“The City to Farm system is meant to model a small-scale, decentralised, local-resources-for-local-use system that, hopefully, other community groups will trial in their areas.

“And if we could do that, then we would be… helping the whole planet, and the farmers would be heroes.

“They’d be climate heroes.”

- RNZ