Each country in the UK has it own heritage agency to identify and protect nationally important designed landscapes.
- English Heritage compiles the Register of Parks and Gardens of Special Historic Interest in England, which includes some 1,600 designed landscapes. Each one is given a grade I, II* or II, in the same way as buildings are listed. The Register forms part of the National Heritage List for England.
- The Northern Ireland Environment Agency maintains the Register of Parks, Gardens and Demesnes of Special Historic Interest which has information on more than 150 of an estimated 300 important designed landscapes in Northern Ireland.
- In Scotland, Historic Scotland compiles the Inventory of Gardens and Designed Landscapes, which can be consulted on-line. So far, 385 of an estimated 3,000 designed landscapes in Scotland have been included on the Inventory. Sites are awarded merits - Outstanding, High, Some, Little or None - in a range of different value categories.
- In Wales, Cadw is the agency responsible for the Cadw/ICOMOSRegister of Parks and Gardens of Special Historic Interest in Wales. There are almost 400 sites on the Register so far. As in England, they are graded I, II* and II.
Of course, many historic parks and gardens do not make it on to a national list, but are still important locally or regionally. Organisations such as the Garden History Society, the Gardens Trusts in England and Wales, and other local history groups carry out research, maintain their own lists and raise awareness of historic parks and gardens in their areas. They also put forward suggestions for landscapes to be included on national registers and inventories.
How is historical importance decided?
The sites on national, regional and local lists include parks and gardens large and small, both public and private, ranging in age from medieval to the late 20th century.
They include a huge variety of landscapes, from Victorian town parks such as Alexandra Park, Oldham to country estates like Berrington Hall or Cawdor Castle. There are city garden squares, like Belgrave Square, and burial grounds such as Dean Cemetery or St Pancras Gardens.
Small plantsman's gardens such as Arduaine sit alongside grand landscapes such as Powis Castle. Medieval deer parks like Abergavenny Priory are included, as well as more modern landscapes, such as Civic Square, Plymouth.
When deciding on the historic importance of a park or garden, each agency varies in its approach, but will look at a range of factors, such as:
- The age of the garden and how many of its kind there are. Lyveden New Bield, for example, is a rare example of a 16th-century garden.
- How much of the original structure remains, and its condition. Antrim Castle, for instance, has well-preserved remains of an early 18th-century formal garden.
- Whether the garden is a good example of a particular period or type of design, for instance the formal Edwardian garden at Hestercombe, or the classical 18th-century landscape of Stourhead.
- Whether it is the work of a known designer, such as William Kent or Humphry Repton.
- Its horticultural or botanical interest, for instance a rare or extensive plant collection, such as the Victorian arboretum at Westonbirt.
- Associations with important people or events in history, like Holdenby House.
- Whether it has been very influential in the design of gardens, for instance Sissinghurst, home of Vita Sackville West.
- Its contribution to local character or the wider landscape, such as Jesmond Dene.
A historic park or garden can combine several of these factors, and often have significant features from a number of different periods, like Tempo Manor. Historic parks and gardens are also often important sites for wildlife and nature conservation.
What protection do registered sites have?
Being on a national register or inventory does not make a park or garden immune from any kind of development, but it does mean that local authorities have to take into account the effect that any proposed changes would have on the site.
Individual elements within a park or garden can also be separately protected: garden buildings can be individually registered, or a tree may be the subject of a Tree Protection Order.
The ways in which parks and gardens are protected varies between the four countries, but in general local authorities are expected to preserve the local historic character and to take historic parks and gardens into account when making plans for their area.
Planners must consider the historic importance of a site when deciding whether or not to grant permission for individual developments. The national heritage agencies are consulted on the most important sites, and where necessary a matter can be referred to a government minister for a final decision.
The Garden History Society has a voice on all applications affecting registered sites in England and Wales.
Landscapes of any kind are by their nature organic, evolving entities, and each heritage protection agency tries to allow for sympathetic development while at the same time preserving the look and character of a historic landscape through the protection of its most significant features, such as buildings, layout and planting.
For more on this subject, see The protection of historic designed landscapes in the United Kingdom.