Methven Castle lies within a designed and planned landscape, which is recorded in a Historic Scotland publication Inventory of Gardens and Designed Landscapes in Scotland. This records the historical, horticultural, architectural, scenic and nature conservation of Methven Castle and its environment as outstanding.
The parkland was laid out in the late 18th century, a large walled garden was constructed in 1796 and an arboretum, thought to be the first in Scotland, was created in 1830. This consisted mainly of conifers which were felled in the 1950’s. The access drive to Methven Castle meanders its way through the former arboretum. From this the largest surviving tree, the famous Pepperwell Oak can be seen. This ancient English Oak (querus robur) has a girth greater than 7m and is thought to be centuries old. The Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) advises that, according to the New Statistical Account of 1845, tradition reports that there is a stone at the heart of the tree