Greening is the process of transforming living environments, and also artifacts such as a space, a lifestyle or a brand image, into a more environmentally friendly version (i.e. 'greening your home' or 'greening your office'). The act of greening generally involves incorporating more environmentally friendly systems into one's environment, such as the home, work place, and general lifestyle.

Greening is also a general term for the appropriate selection and planting of plants on, in, or next to buildings and in public parks. The goal of greening is usually a combination of environmental benefits and improving the visual design of surfaces, for example, a green wall or green roof, as well as the creation of green spaces. This usually requires technical measures such as earthworks or supporting climbing plants. Furthermore, permanent care and irrigation is usually necessary to maintain the greened environment. In some areas there are normative requirements for the planning and execution of the greening, for example roadsides greening. In soil bioengineering, plants with technical functions may be needed.

Measures such as the recultivation of heaps, plantations as part of a compensatory measure or, in tiller forestry, the planting of vegetation are distinguished from greening. In professional parlance, the sowing or planting of agricultural crops is also referred to as crop growing or occasionally as field cultivation. The term sowing is used for lawns.

The greening of deserts is a particularly difficult task. If it is sustainable, it is the most effective measure for the economic development of arid areas, decreases global warming, and also improves the local climate. The state of Israel in Negev has long been a pioneer in this field. A project between 1991 and 2011 and supported by, among others, the forests of German states provided 450,000 trees for the desert city of Beersheba. Another major reforestation (greening) project is China's Green Wall, which aims to reduce the increasing devastation of entire regions in the north and west of the People's Republic of China.