How forests the size of tennis courts transform Australian cities

You’ve heard of tiny homes, but what about tiny forests?

A movement is growing in Australia to plant dense, diverse forests on plots of land as small as a tennis court.

The tiny forests, scientists say, deliver outsize benefits by reducing urban heat, locking carbon in the soil, reducing run-off and localised flooding, and boosting biodiversity.

Also called pocket, micro or Miyawaki forests, the sites planted so far in Sydney, Melbourne, Perth, Canberra and many regional towns are also proving more resilient to weed infestations than other forms of bush regeneration.

The method was pioneered by Japanese ecologist and botanist Professor Akira Miyawaki in the 1970s, but took off internationally in about 2015 with a project in the Netherlands. It involves preparing the site with soil remediation, studying the original plants that would have grown there and trying to replicate that from shrub to canopy level, and planting three to five plants per square metre.

Dr Alex Callen, a restoration ecologist at the University of Newcastle, said scientists were watching the trend closely because it had been unclear how the Miyawaki method would translate to Australian ecosystems and landscapes, especially with rainfall becoming more unpredictable because of climate change.

“Even though the data is pretty young – most tiny forests have only been studied [for] between three and 10 years and that’s not a long time when you think that forests can take hundreds of years to mature – we are seeing very high success rates compared with traditional ecological restoration work,” Callen said.

“We’re also seeing very limited weed invasion – and weed invasion in ecological restoration sites in Australia is one of the number one reasons that they fail.”

Not-for-profit group Groundswell Collective has established 20 tiny forests since 2023, mostly in NSW – on the Central Coast, in Lake Macquarie and the Hunter region, and Orange in the Central West – and one in the Cook Islands.

Charity Earthwatch has partnered with councils to plant a number of tiny forests in urban areas – including Glenfield and West Pymble in Sydney and Glen Waverley in Melbourne.

Ecologist Dr Grey Coupland has driven the concept of tiny forests in Perth, particularly in the city’s schools, while in Canberra, landscape architect Edwina Robinson has been a key proponent.

There’s one in Moorooka in Brisbane. And in Tropical North Queensland, a larger plot of land has been planted according to the method – Dingo Pocket Miyawaki Forest, which spans 750 square metres, but is densely planted with 3000 seedlings from 50 native rainforest plant species.

Callen said there was a lot of evidence about how tiny forests counteracted urban heat because of the cooling effect of more plants in the ground. The research on biodiversity was still emerging, but was promising because the structure of the vegetation mirrored mature forests.

“We know that when we plant densely and when we plant pioneer plants – early colonisers of space – with plants that grow more slowly into canopy, what we’re doing is hastening a forest to maturity,” Callen said.

“That gives it what’s called structural complexity, which means there are more places and spaces and resources for plants and animals to live, and that’s a very good thing.”

Callen said the location of the tiny forests and whether they connect patches of remnant vegetation would also determine biodiversity value.

Anna Noon, founder and director of partnerships and programs at Groundswell Collective, said there were also social benefits.

“They connect people to nature, they connect people with each other, they help with wellbeing and resilience and providing hope for the future,” she said.

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