Houses fronted by more street trees experienced lower crime rates than houses without street trees.

An interesting article explores the connection between street trees and human health. Check out Growing Quality of Life: Urban Trees, Birth Weight, and Crime by John Kirkland. There is a summary of the article below.

City dwellers can find many reasons to value neighborhood trees. Urban greenery provides relief from the built environment that many people find appealing. In fact, a previous study found that a tree in front of a home increased that home’s sale price by more than $7,000. Two new studies explore the measurable effects that urban trees and green spaces have on human health and crime rates.

Geoffrey Donovan, an economist and research forester with the Pacific Northwest Research Station, used public health data, crime statistics, tax records, aerial photos, and other information in the two recent studies. He found that women who live in houses with more trees are less likely to have underweight babies. The study on crime revealed a more complex relationship. Larger trees, including trees located near the street, are associated with a lower incidence of property crimes. Larger numbers of smaller trees—especially trees planted near the home, which may provide a screen for burglars—are associated with higher crime.

Cities within the Portland, Oregon, metropolitan area are using this information as they rewrite street tree regulations. Likewise, local crime prevention programs and tree planting advocates are sharing the findings with urban residents.