Take a vacant lot in Philadelphia, green it up and reduce crime.
A University of Pennsylvania study published online in the American Journal of Epidemiology shows vacant lots that have been cleaned and greened as part of a Pennsylvania Horticultural Society program have reduced gun assaults and vandalism in some of those areas.
PlanPhilly reports the study evaluates the effects of the program, which began in 1999 and involves removing trash, grading the land and installing a low fence around what used to be empty lots.
By 2008, almost 4,500 vacant lots had been tended to, and police data in four sections of the city show a decline in crimes around those properties.
One type of crime did go up: acts of disorderly conduct increased once people had a nicer-looking place to gather.