Pettigrew began working at Dumfries House in Ayrshire, before transferring to the Bute estate in South Wales in 1873.

[7] In an innovatory step, Bute determined to introduce commercial grape vines at Castell Coch in 1873.

Created in 2011 by the architect Michael Davies, the door includes nine panels featuring people, events and structures related to the area.

[17] He was succeeded in this role by his brother, Andrew Alexander, when he took up the post of Chief Parks Officer at Manchester in 1915.

He subsequently transferred to the earl's South Wales estate, St Fagans Castle when he remained until his retirement in 1935.

[22][23] The youngest son, Andrew Alexander trained with his father, during which time he travelled to China and Japan to study horticulture and flora, and at Kew.

[24] He worked with his brother Hugh at St Fagans, before succeeding to the post of head gardener to Lord Plymouth at Hewell Grange, where he remained from 1900 to 1915.

He then returned to Cardiff to take up the Chief Parks Officer role vacated by his eldest brother William and continued in this post until his death from cancer in 1936.

[25] During his tenure, he wrote a seven-volume study, The Public Parks and Recreation Grounds of Cardiff.