The present landscape structure was laid out in the late 18th/early 19th century and development of the components within has continued since the late 19th century.
The lands of Logan, originally called Balzieland, have belonged to the McDouall family for some 700 years. Dougal McDouall was granted the lands in 1295. Sir Herbert Maxwell noted that they were the only family in Galloway of Pictish origin. The early records of the family history were lost, together with the original castle, in a fire in 1500; the remains of this castle stand in the walled garden. A new charter was procured by Patrick McDouall in 1504. Subsequent historical records are not concise; 180 years later, Robert McDouall built the pier and applied to the Privy Council for a licence to develop Port Logan.
The present house was built in 1702. Colonel Andrew McDouall made many improvements to the estate in the late 18th and early 19th century. The structure of the present designed landscape was established by c.1860 (the date of the 1st edition OS map). It was further developed by James McDouall and his wife Agnes, great- aunt of the present owner, shortly after their marriage in 1869. They commissioned David Bryce to alter the house. Much of the plant material for the gardens, in particular roses and lilies, came from Mrs McDouall's family home, Smeaton Hepburn in East Lothian. Their sons, Kenneth and Douglas, continued to develop the gardens. Inspired by their mother, they travelled extensively and brought plants back from abroad.
On the death of Mr Kenneth McDouall in 1945, the Estate was inherited by Sir Ninian Buchan-Hepburn, the present owner. Between 1949-1970 the house and garden were owned by Mr Olaf Hambro but managed by his Trustees. During this period, the walled garden was gifted to the Secretary of State for Scotland to be managed as an annexe to the Royal Botanic Garden, Edinburgh. The house, stripped of its Victorian additions, was restored to its original Queen Anne proportions but not exactly reproducing the original. Logan today is continually under development by Sir Ninian Buchan-Hepburn, who bought back the house, garden and policy woodlands in c.1970.
Logan House, listed category A, is a fine Queen Anne house completed in 1702; earlier construction can be identified in the cellar. The house was subject to extensive additions by David Bryce in 1874 which left only the original back wall exposed. These additions and the wings of the 18th century house were removed in 1949.
Statues of Owls stand on the terrace next to Logan House. Stone Owls were salvaged from the demolition of the Victorian house. Stone urns stand on the terraced walls to the east of the house.
The parkland lies to the east and west of the central axis of woodland and garden which forms the core of the landscape. The parks were laid out c.1800 and were extensively improved between 1870 and 1920. The loch in the Dam Park was enlarged in 1901 it is now obscured from the house by alder. Monkey puzzle trees (Araucaria araucana), of about 100 years old, line the edge of the pond. The park is now largely open pasture with occasional clumps of trees and a few individual specimens. The clumps of trees are composed largely of beech with some oak, dating from about the 1870 period. The number of clumps has been reduced since c.1910. The park immediately west of the house has been developed as part of the woodland garden. The north drive approaches the house along the edge of Dam Park. The east drive, now diverted to provide vehicular access to the Botanic Garden, cuts through the park from the B7065.
The woodlands are of particular importance at Logan due to the shelter they provide from the prevailing westerly winds. The original, predominantly beech, woodlands of c.1800 are now in decline. However, beech remain in an area to the north of the house, to the east on Court Hill Plantation and to the south in Glen Plantation. Some hardwood replacement has taken place and most of the larger woodlands, particularly in the north of the site, have been planted with mixed conifers since the last war. Broadleaved belts have been left to regenerate and have been replanted along some edges. A picturesque walk called The Primula Walk runs through the southern woodlands to the shore at Logan Fish Pond which is carpeted with Primulas during the spring. The walk is bordered by rhododendrons, mostly planted in the early 19th century.
The Woodland Garden was established by Mrs Agnes McDouall, great-aunt of the present owner, from 1869 and continued by her two sons and their cousin, Sir Ninian Buchan-Hepburn. Part of the original woodland garden is now incorporated in Logan Botanic Garden. Species Rhododendrons form the structure, many raised from seed from expeditions of George Forrest and Reginald Farrer. Other natives of temperate zone countries were introduced to the garden and have become well-established. The garden hosted a respected collection which was described in the Gardeners' Chronicle in 1901 and 'The Garden' in 1924. The density of planting was such that extensive thinning was required in 1954 which revealed many fine R. arboretum specimens.
Within the garden are a series of smaller gardens. To the north-west of the house lies the Hen-Knowe shrubbery, where Rhododendrons predominate. South-west of the house, in the Monkey puzzle shrubbery, are several fine Eucalyptus, planted in 1922; among them, E. coccifera and E. globulus. In the Octopus Garden south of the house are some fine Embothrium, in particular E. lanceolatum `Norquinco Valley', E. coccineum and the variety `Logan Damaris' raised by Kenneth McDouall at Logan in the 1930s.
The Cow Park Shrubbery extends along the east boundary of the garden between the house and the park south of it lies the Bog Garden. In the scree garden, created in the 1940s, are some fine specimen shrubs, especially Olearias. Plants of particular interest in each garden are noted in the guidebook prepared by Sir Ninian Buchan-Hepburn. There are a number of significant specimen trees in the garden about thirty of which were measured by Alan Mitchell in 1979.
Formal grass terraces provide a setting to Logan House and an effective transition between Logan House and the woodland garden. A raised terrace was created at the east front of the house in c.1949 using masonry from the Victorian front of the house which was demolished at that time.
The Walled Garden is situated to the south of Logan House and incorporates the area which was the kitchen garden but was converted by Mr Kenneth McDouall to provide habitats for his most tender plants. It was gifted to the Secretary of State for Scotland in 1969 and is managed as Logan Botanic Garden which is the subject of a separate report.