The following text is from the original listed building designation:
HAWKHURST WATER LANE TO 7630-7730 (east side)
17/453 Walled garden with glasshouses about 100 metres south-west of Tongswood GV II Walled garden and glasshouses. Mid to late C19. Red brick. Walls about 10 feet high, with regular buttress piers, capped and extending about 60 by 100 metres, the entrances on north and south walls framed by capped piers with ball finials, the walls ramped down to the piers. East and west walls pierced by single doors, with baluster-screen upper panels, with segmental heads, and framed by paired buttresses. Attached to the exterior of the east and south walls are single storey lean-to storehouses and cottages, with ranges of glasshouses, with red brick bases; lean-to against east wall, and ranged in south-west corner.
Listing NGR: TQ7766430635

Not on 1st or 2nd edition Ordnance Survey 25" mapping, suggesting very late 19th century date, or even early 20th.

English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.