English Heritage registers only those sites which it considers to be of special historic interest.
As a guide to the level of historic interest required to make a site 'special' nine criteria have been drawn up to asses whether to register a site. The application of these criteria, however, must be accompanied by expert and extensive knowledge of the country's historic parks and gardens as a whole, to ensure that decisions are consistent.
The older a designed landscape is, and the fewer the surviving examples of its kind, the more likely it is to have special interest. The following chronology is meant as a guide to assessment; the dates are indications of likely periods of interest and are not absolute. In summary, sites likely to be designated are:
Sites formed before 1750 where at least a proportion of the original layout is still in evidence
Sites laid out between 1750 and 1840 where enough of the layout survives to reflect the original design
Sites with a main phase of development post-1840 which are of special interest and relatively intact, the degree of required special interest rising as the site becomes closer in time
Particularly careful selection is required for sites from the period after 1945
Sites of less than 30 years old are normally registered only if they are of outstanding quality and under threat
Further considerations which may influence selection, and may exceptionally be sufficient by themselves to merit designation, are:
- Sites which were influential in the development of taste, whether through reputation or reference in literature
- Sites which are early or representative examples of a style of layout or a type of site, or the work of a designer (amateur or professional) of national importance
- Sites having an association with significant persons or historic events
- Sites with a strong group value with other heritage assets
These criteria are not mutually exclusive categories and more than one of them may be relevant in the assessment of any particular site.
Age and registration
The first five criteria are a set of date bands, which broadly mirror the main trends in the history of the development of gardening and landscape design. A parks or garden where the design and layout is particularly old (early 18th century or older) are rare, and is likely in itself to make a site sufficiently 'special' to be registered.
Broadly, the more recent the structure of a garden, the more likely it is to have survived and the more common that type of site is likely to be. As a result the selection process is more selective and for more recent sites to be nationally recognised, they have to have something in particular that makes them 'special', and this is where the last four criteria come into play.
Influential sites, major designers and good standard examples
The added 'extra' could be that the park or garden has been laid out by a nationally famous designer, that it became famous or well-regarded in its day, or that it had a strong influence in changing fashions. It could also be that the site is a very good example of its type.
Close and direct associations with nationally important people or events can make a site more historically interesting than its layout alone suggests. In such a case, we consider the importance of the person or event, and the importance of the park or garden in relation to the person's life and work, or in relation to the event in question.
To be eligible for registration, there must be a direct link between a site and a person or event, and this must be reflected in the actual layout of the site itself.
When a park or garden is of historic interest, but not sufficiently important in its own right to merit registration, it may still be eligible to be included on the 'Register' if it provides strong group value with buildings, with other land, or with a group of other registerable sites, providing this link is in itself of special historic interest.
The setting of a major historic building might, for example, be carefully designed to form a piece with that building; alternatively, a garden might form an important element within a fine example of town planning. A leading designer might have laid out a set of related sites within an area, most of which are clearly of registerable quality. There may be one which is not so clearly so: it might still prove registerable as part of the set.
The 'Register' criteria can be rather misleading; it suggests that parks and gardens were usually laid out within a given date-band and changed little after that time. In fact the reverse is in fact the case. The majority of parks or gardens will have developed as a series of additions or alterations as needs and fashions changed.
Each phase of development would have varied in its impact on the landscape and its degree of interest. With such sites, it is the sum of the developments as seen in the landscape today which is considered. The value of a site can rest in the very fact that its present form is the outcome of a series of phases of development or a continuous sequence of change.
The development of some sites is particularly well recorded in archives and published material. Where such records have survived they add to our understanding of the site and can contribute to its interest.
Condition and registration
While the 'Register' seeks to discover sites of special historic interest, it is today's landscape that it is concerned with, rather than any lost landscape of the past. No matter how important a site once was, if it no longer exists, having been lost for example to irreversible development such as housing, it will not be registered.
Sadly, many sites are now in poor condition, with flower beds grassed over, neglected borders, parkland ploughed up and features in ruins. However, such a state will not necessarily render a site un-registerable if its overall design or layout remains sufficiently intact.
Plants and the 'Register'
For many people, the mention of the word garden conjures up a vision of floral beauty or culinary possibilities. While English Heritage appreciates good gardening, when compiling the 'Register', it looks at the more permanent elements in the landscape such as landform, built structures, walks and rides, water features, structural shrubberies, hedges and trees. It does not focus on the ephemeral, shorter-lived plantings of herbaceous perennials, annuals, roses, and most shrubs.