Urban reforestation is the practice of planting trees, typically on a large scale, in urban environments. It sometimes includes also urban horticulture and urban farming. Reasons for practicing urban reforestation include urban beautification, increasing shade, modifying the urban climate, improving air quality, and restoration of urban forests after a natural disaster.
Large scale urban reforestation programs include New York City's Million Tree Initiative, and TreePeople in Los Angeles, which planted 1 million trees in preparation for the 1984 Summer Olympics and continued planting thereafter.
Grassroots efforts include Friends of the Urban Forest in San Francisco which advocates the planting of street trees and the Urban Reforestation organization in Australia, which focuses on sustainable living in urban places.
Urban reforestation efforts compete for money and urban land that could be used for other purposes. For example, effort placed in planting new trees can take away from maintenance of already established trees.