Grade 1 listed landscapes are rare.
Here is a brief description of the significance of the formal gardens and parkland at Bicton:
Original layout of the formal gardens with its axial vista dates from c 1735. But the present appearance of this and the surrounding park land is largely the work of John, Lord Rolle, and his second wife Louisa Trefusis on the advice of W S Gilpin circa 1830/40. The reason for this high designation is that the parkland, designed by Gilpin, was in his distinctive style of clumps of trees planted in an “amoeboid pattern”. The lake he created at Bicton has inlets and promontories mirroring the outline of the tree planting. It is quite simply unlike anything usually encountered in an English landscape park. Comparatively few of his designs survive in a recognizable form today.
(see article in The Devon Garden Trust Journal Issue 2, September 2009. Author: Kim Auston, Landscape Architect Western Territory for English Heritage.)
Ownership is complex as described in Wikipedia:
[Note: The Rolle family, mentioned above with estates in East Devon, merged with the Clinton family in 1907. The Clinton estates were based in North Devon. This left them with two Mansion houses.]
“The 21st Baron [Clinton] let and later sold the [Bicton] mansion house and surrounding lands to Devon County Council as an agricultural college [from 1947], now Bicton College, which as of 2016 covers 490 acres (200 ha), and sleeps 231 residential students.The gardens at Bicton were renovated by the baron in the 1950s and opened to the public in 1963. The 22nd Baron [current Lord Clinton] gave the botanical gardens to a charitable trust in 1986, which sold them in 1998 to Simon and Valerie Lister who turned their 63 acres (25 ha) into a commercial visitor attraction named Bicton Park Botanical Gardens. The remainder of the land comprising the former manor of Bicton is still owned by Baron Clinton under the management of Clinton Devon Estates. This includes 17,000 acres (6,900 ha) of tenant farmland, 4,700 acres (1,900 ha) of woodland and 2,800 acres (1,100 ha) of the East Devon Pebblebed Heaths. The equestrian venue known as Bicton Arena is also part of the estate.”
From Historic England at risk register:
C18 and C19 country house estate developed from earlier manor. Large park, important gardens and arboretum. Registered park in three main ownerships. The core of the site, including the principal house, has been developed in the post-war era as a land-based college. Continuous pressure for development as the college has expanded has tended to erode the integrity of the designed landscape. The absence of a masterplan to guide and inform development remains a major cause for concern.
Park and garden
Generally unsatisfactory with major localised problems
Mixed, multiple owners
Registered Park and Garden grade I, 19 LBs, SM