Greening in style: urban form, architecture and the structure of front and backyard vegetation

Residential yards comprise most land and green space across cities. Despite yards being ubiquitous, little comprehensive information exists on how vegetation varies between front and backyards. This hinders our ability to optimize greening interventions on private urban land. We devised an accurate GIS algorithm to locate and classify front and backyards within residential landscapes. By applying this method to the greater Boston area, we measured vegetation structure (i.e., canopy cover, height and volume) of front and backyards with LiDAR and multispectral imagery. We further investigated relationships between urban form, architectural style, socio-economics, and the structure of front and backyard vegetation across Boston's residential landscapes. Among the 85,732 residential parcels that were not corner lots and had cadastral and architectural data available, backyards were twice as large as front yards on average and had significantly greater canopy cover, vegetation volume and taller trees. Parcel-level characteristics, including vegetation in the corresponding front or backyard, as well as morphological characteristics of parcels, were the best predictors of vegetation structure. House architectural style was related to vegetation structure. The neighborhood socio-economic characteristics were the least important factors in predicting yard vegetation structure. Our study highlights that urban greening in yards depends on urban form and morphology at the parcel scale, and as such, it could be enhanced through urban to provide opportunities for additional vegetation. Architectural style might represent a further filter by which residents manage vegetation in their home environment, making it possible to devise strategies to green our cities – in style.