When did landscaping start?

According to newly published research from Harvard University, the development of cities in Mesopotamia between the Tigris and Euphrates rivers in the fifth millennium B.C. included considerable landworks. These were used to improve building sites and roadways but also to preserve arable land around the city. The silty nature of river soil in that region makes it subject to wind erosion and plantings and windbreaks were constructed to protect the food producing areas. Also, the early cities such as Ur were considerably larger than previous research postulated and involved huge government complexes complete with date palm groves and water gardens.