The Bushy Park and Home Park SSSI has been designated because of the exceptionally large numbers of ancient and veteran trees growing on the site, its internationally significant populations of rare insects, and the presence of extensive areas of special grassland habitat.
The trees at Bushy Park and Home Park are survivors of wood-pasture management dating back to the 15th century. More than 200 veteran trees have been identified at the site, with 94 classed as ancient. Only 44 sites nationally are known to support more than 100 veteran trees.
Oak, lime, horse chestnut and sweet chestnut feature along with 16 other species of tree - notably a large number of very old hawthorn trees, many festooned with mistletoe.
The great age of many of the trees also provides habitat for many rare species of wood feeding insects. The site ranks amongst the top five in Britain for this highly specialised group of creatures, for which Britain has international importance.
Most of the 540ha site is held in trust by the Crown Estate. Bushy Park is managed by The Royal Parks and Home Park by Historic Royal Palaces.