Urban greenery provides ecosystem services that play an important role in the challenging context of urban deprivation and poverty. This study assesses the social importance of vegetation through empirical assessment of 44 urban slums in the rapidly developing southern city of Bangalore, India. Vegetation played a major role in supporting nutrition by its role in food consumption, and in promoting health through the planting of species with medicinal use. Trees in slums also formed nodes for social activities including conversing and playing, domestic activities such as cooking and washing dishes, and livelihood activities such as the manufacture of broomsticks and tyre repair. Innovative methods of gardening were widely adopted, with kitchen gardens found planted in plastic bags, paint cans, old kitchen utensils and buckets, indicating the importance given to planting in environments with limited finances. Short and narrow trunked trees with medium-sized canopies and high economic value, such as Pongamia, were preferred. A greater focus on greening in slums is needed, and can provide an invaluable, inexpensive and sustainable approach to improve lives in these congested, deprived environments.