We use a hedonic price model to simultaneously estimate the effects of street trees on the sales price and the time-on market(TOM)of houses in Portland, Oregon. On average, street trees add $8870 to sales price and reduce TOM by 1.7days. In addition, we found that the benefits of street trees spill over to neighboring houses. Because the provision and maintenance of street trees in Portland is the responsibility of adjacent property owners, our results suggest that if the provision of street trees is left solely to homeowners, then there will be too few street trees from a societal perspective.