In 1607 there were ten pools on the brook west and south of Highnam Court. To the west were Shoell Pool, Horse (later Dog Kennel) Pool, and Orchard Pool, while to the south were seven smaller stews, presumably of medieval origin. To the east, in the fork of the Ross and Newent roads, was the 4.5ha Great Pool. In the mid 18th century there was a simple formal garden south-east of the house, but in the early 1770s work was in progress on a new garden, part of the improvements at Highnam made by John Guise. Trees in the Wilderness to the south of the house were felled, pines, shrubs and other plants were brought from Piercefield (Monmouthshire), a kitchen garden and hothouse were constructed, and a new drive laid out. The grounds were considerably altered again in the early 19th century : the chapel by the south-east corner of the house was demolished in 1807, the seven fishponds south of the house were enlarged to form The Lake in 1809-10, and (after a pause occasioned by a ruinously expensive election campaign of 1810) the Great Pool was drained in 1817-18. In 1841, three years after he bought the estate, T G Parry began work on the grounds. The south, former entrance, front received a new terrace and formal lawns, beds, and walks were laid out east and west of the house. The two southern ponds of the three to the west of the house were drained in the 1840s for the construction of the Pulhamite Winter Garden, undertaken in phases between 1849 and 1862, which was planted with ferns and evergreens. It was also in Parry’s time that many of the conifers were planted. In the C20 the gardens fell into serious disrepair. The extensive restoration programme, started by the current owner, Roger Head in 1993, still continues and has resulted in the magnificent gardens that you can see today.
Full account can be found at www.historicengland.org.uk