Green Spaces

There are plenty of reasons to like green spaces in cities: they’re pretty, they catch stormwater runoff, they improve health. And now a new body of evidence is coming into focus on how urban nature affects crime. It appears that the way we take care of our trees, shrubs, and lawns makes a difference for the safety of the surrounding area.

The field of research is still pretty young, but recent studies have found significant associations between green space maintenance and certain types of crime. The exact mechanism is not yet known, but one theory harkens back to Jane Jacobs’ notion of “eyes on the street”: well-kept lawns and community plots encourage more people to spend time outside in those spaces, leading to a greater degree of informal surveillance of the area and deterring crime.

Taken together, this research gives cities reasons to reassess policies about cleaning and greening vacant lots, developing parks, or catching stormwater in green installations. Beyond the ecological and aesthetic benefits, these investments create a safer environment for the people who live nearby.

Crossing over to private property, research suggests that well-maintained residential gardens are associated with lower crime rates than poorly maintained gardens / lawns. Scientists conducted detailed surveys of 1,000 houses, then cross-referenced them with data on crimes reported within 150 meters of each property. The analysis, published in the journal Landscape and Urban Planning, found 10 statistically significant landscape characteristics.

“The level of maintenance of the garden is almost like a neighbourhood watch sign saying, ‘We have eyes on the street and we will say something.’”

The most powerful indicators of a decrease in crime were having a lawn, the presence of garden hoses or sprinklers, shrubs, tree cover, and the presence of trees. The factors most strongly tied to more crime were the number of small un-kept bushes, hedges, trees, litter, uncut or dried out lawns.

It’s hard not to see the income-related implications of this: If you can afford to live in a leafy neighbourhood and maintain a lawn with plentiful bushes and trees, chances are you’re in a safer place than if you live in a trash-strewn block with a dried up, un-mowed lawn and a bunch of weed trees left unattended along the roadside.

But there’s more to it than that, says author Morgan Grove, who’s also a researcher with the Forest Service. Criminals tend to look for spaces where they can operate without being seen, or where if they’re seen they won’t be reported.

“The level of garden maintenance is almost like a neighbourhood watch sign saying, ‘We have eyes on the street and we will say something,’” Grove says. “There’s a physical fact, which is that people can see criminals, but also this symbolic meaning that reinforces the social order that people will act upon their own behalf and on behalf of others.”

Whereas the “broken windows” theory suggests criminals look for physical signs of neglect when scoping out targets, this study supports the “cues to care” theory, that visible maintenance of shared spaces presents “a sign of social capital and cohesion that might deter criminals.”

The upshot: Urban greenery should play more of a role in cities’ plans to reduce crime. A good first step would be increasing public attention to landscaping and assisting residents in taking care of their own lawns and gardens. This brings more urgency to cities’ maintenance of vegetation on public land.

A dead or un-cut hedge on the road side isn't just un-cut hedge anymore!