Peartree Green is near the site of the historic Supermarine Factory, known for its production of seaplanes and the Spitfire. During World War 2, air attacks aimed at the factory caused major destruction of the houses on the Green and left significant bomb craters. In the 1970s chalk from the construction of the M27 motorway was laid at the bottom of the Green, covering areas used for landfill in the 1960s and this has created a unique habitat for several varieties of orchids and insects.

History and careful management of the Green has encouraged plants and insects, rarely seen in other areas of the city, to thrive and include pyramidal orchid, marbled white butterfly and more recently white letter hairstreak butterfly. The flora and fauna of Peartree Green is regularly surveyed by Phil Budd, Southampton Natural History Society and other volunteers. They have kindly provided a list of species recorded.