Urban vegetation has many recognised biological and human use values. Often described as the Urban Forest, this vegetation includes both remnant natural and designed vegetation, native and exotic species, parks, riparian and coastal areas, street trees, plant collections, civic spaces and many other components. This paper draws from a Master’s research project surveying the biodiversity and management practices associated with thirty-nine tree collections in the Auckland area. These tree collections make up a specific component of the overall urban vegetation mix of Auckland. In this paper, selected biodiversity highlights are illustrated from the collections surveyed, and a range of tree collection management factors such as databases, mapping, and management planning are discussed.