Hay Castle (nprn 25593) is a small site with a strong historical interest. Its gardens are contained within the medieval boundary of the outer castle ward. To the north, the remains of a formal seventeenth-/eighteenth-century terraced garden descend a steep slope directly below the house to Castle Street.
On the south, there is a small circular level lawn, which is partially wooded and enclosed along its southern boundary by yew, laurel and rhododendron planted on a south-facing bank. This area covers approximately 1/4 acre (0.1ha), and an old, circular drive runs around the periphery of the south garden which is enclosed by a stone wall, the area entered through a pair of fine seventeenth-century stone gate piers set in the south-west of the boundary wall alongside Oxford Road. 

Sources point to former developments and plantings though their dating is uncertain. It is unlikely that gardens were created here before 1485 except for possible orchards on the south. A view of 1741 shows at least five terraces descending the north front, linked by a central flight of stone steps, with large yew or box topiaries at regular intervals on each terrace. The view also records ornamental orchards on the eastern slope of the site, above Castle Lane. Four long, rectangular beds with four, square beds are illustrated, bordered with ornamental fruit trees. No evidence of any flower planting is known until the late nineteenth-century. The age and condition of the surviving trees in the garden suggest that most were planted from about 1860/70. No kitchen gardens have survived at the castle site and no reference to any has been found. However, land to the south of the site, beyond Oxford Road, purchased in the nineteenth century, was used as ‘Castle Gardens’, elements of which have survived more recent urban developments; the north part of it, an orchard in the nineteenth century, is now a carpark but the south-west extent is under grass with two trees near its centre. 

Sources:
Cadw 1999: Register of Parks and Gardens of Special Historic Interest in Wales, Powys, 124-6 (ref: PGW Po11(POW)).
Additional notes: D.K.Leighton

RCAHMW, 29 June 2022