The avenue was planted in 1863 by Piers Patrick, a wealthy American who had bought the estate the year before. Initially 50 sierra redwoods (Sequoiadendron giganteum) were planted to form the foundation of the avenue that can be seen today. Piers Patrick began the process of planting which was continued by subsequent owners. The avenue now forms one of the finest entrances to any botanic garden anywhere in the world.
In the wild the sierra redwoods are native to the western slopes of Sierra Nevada in California and may live 3,500 years, reaching over 91m and weighing 6,000 tons. Their longevity is attributed to their massive trunk buttresses and to the red-brown bark which can be up to 60cm thick, making the tree partially fire resistant.