The Sir Harold Hillier Gardens is an arboretum comprising 72 hectares (180 acres) accommodating over 42,000 trees and shrubs in about 12,000 taxa, notably a collection of oaks, camellia, magnolia and rhododendron.

[2] Run as a registered charity, the Gardens are continually developed to further Sir Harold’s philosophy of horticulture, conservation, education and recreation.

[4] The collection includes Metasequoia glyptostroboides, from the original batch of seed received by the Arnold Arboretum from China and distributed in 1948, its first introduction to the West.

This three year trial was in association with the Royal Horticultural Society and led by curator David Jewell.

The aim of the trial was to establish garden worthiness, resolve any naming problems and assess their medicinal properties.

At a press day in 1964, a journalist asked Sir Harold what he thought of the fledgling garden plant conservation movement.

[6] The Herbarium is located within Jermyn’s House and was founded in 1995 to accommodate specimens collected by Sir Harold Hillier.