Walk on the wild side
Our obsession with manicured, herbicide- and pesticidecontrolled lawns has created green spaces “barren of beetle and bee” that contaminate groundwater and create more greenhouse gases than they soak up.
Our obsession with manicured, herbicideand pesticide-controlled lawns has created green spaces “barren of beetle and bee” that contaminate groundwater and create more greenhouse gases than they soak up.
Maria Ignatieva’s world is crisping to brown. In Perth, where she works at the University of Western Australia, the mercury is climbing to a Saturday high of 40°C – the hottest November day since records began in 1897 – exacerbating conditions that are fuelling fires across much of the continent.
In the city, indigenous plants are coping with the heat. “They are designed for that,” Ignatieva says, on the phone from her downtown apartment. “That is why they don’t look lush and green.” But, to keep the naturally sandy city looking like a rain-soaked European landscape, the uniform carpets of grass are on a life-support system of precious groundwater.
As in all the cities the Russian-born landscape architect and botanist has lived in – St Petersburg, Syracuse, Uppsala in Sweden, Christchurch and now Perth – the garden, she says, “is still a big deal”. By “garden”, she means those vast expanses of private and public land covered in short-cropped, often exotic grass
– a global homogenous landscape that, she says, can result in a loss of local identity and biodiversity and increases the costs of maintenance and management.
“We don’t need to cover all the leftover parts of the city with rugs of green grass. Particularly with climate change, we need to create a new urban environment that can cope with such temperatures.”
City planners and landscape designers, she says, have a role in promoting different planting programmes, design configurations and palettes better able to handle rising temperatures and diminishing groundwater – Ignatieva is working with the turf industry to identify such species – “but when you compare [more resilient species] with green-lawn turfs – how do you get people to accept more sustainable browns and yellows? People’s acceptance of different aesthetic patterns is the most difficult part.”
It is a near-global conundrum. Worldwide, including New Zealand, demand for pasture for grazing has been responsible for huge tracts of deforestation. As fires burn across the Amazon forest, figures from Brazil’s National Institute for Space Research show that, in July this year, the rainforest lost 2,254sq km of vegetation, fuelling fears President Jair Bolsonaro’s pro-agribusiness stance will further accelerate deforestation and the risk of out-ofcontrol fires. Our cities, too, are turning a uniform shade of green. Research by Ignatieva and landscape ecologist Marcus Hedblom, published in Science last year, found lawn covers about 70% of open urban spaces in modern cities worldwide – in the US, lawn grass is the largest irrigated non-food crop in that country, covering about 163,000sq km. Extrapolating their data, they say the flat green grass cloaking playgrounds, sports fields, golf courses, river banks, berms, reserves and private lawns now covers up to 800,000sq km of the world’s surface – about the size of Pakistan – including wildly inhospitable environments such as Dubai and parts of China.
New Zealand is no different. Between 15% and 20% of Auckland is grassland – that’s an estimated 150-200sq km of green. More than 70% of Christchurch’s urban green space is given over to lawn; a survey of south-western suburbs found on average just under a half of each residential property is grass
These lawns require work. As New York Times Magazine writer
Michael Pollan famously claimed, “Gardening means war.” It’s war against drought – Ignatieva’s study found households in arid regions of the US direct three-quarters of their water use to watering their lawns; even with summertime watering restrictions, Perth uses 73 billion litres of groundwater to irrigate its public green spaces each year – private homeowners pump an additional 72 billion litres of water from unlicensed backyard bores.
And it’s war against weeds and insects. Around the world, herbicides, pesticides and fertilisers are deployed to encourage the growth of a single species of grass, leaving a weirdly quiet biodiversity desert, writes British horticulturalist Alys Fowler, “barren of beetle and bee”.
Lawn covers about 70% of open urban spaces in modern cities worldwide – in the US, lawn grass is their largest irrigated non-food crop.