Prior to 1927, a kitchen garden and nursery associated with Clanranald's house in the Glen (part of which survives as Glen House) lay on the site of Làrach Mòr. These were laid out probably in the mid 19th century. It was set out regularly, in a grid of six compartments by paths and surrounded by further regular plots (1873, OS 6"; 1899, OS 6"). The valley sides were covered with semi-natural woodland, including a few planted hardwoods and conifers.
John Augustus Holms (d.1938), a Glasgow businessman, created the woodland garden at Làrach Mòr. An art connoisseur, collector and authority on the fine arts, porcelain, silver and carpets, his great love was gardening. He commissioned Sir Robert Lorimer to design his house, gardens and park at Formakin, near Bishopton, Renfrewshire where, in the early 1920s, he developed an extensive collection of Rhododendron (q.v. Inventory, Volume 2, pp.254-9). He was a founder member of the Rhododendron Society and his enthusiasm and promotion of the genus led to his commemoration by the naming of Rhododendron arboretum cultivar 'John Holms', which received an Award of Merit in 1957.
During his years at Formakin his interest in the genus Rhododendron grew. Eventually his collection outgrew the garden so he searched for a site on which to develop his collection further. The west coast offered optimum conditions, with its milder climate. In 1927, he acquired the lease of 28 acres of the Arisaig Estate. This comprised a woodland which included some large broadleaf trees, a stream and varied topography with the potential for exploiting the natural setting which offered the necessary protection and habitat for Rhododendron.
He moved a large number of specimens from Formakin to Làrach Mòr and added continually to his collection from elsewhere. He set out to obtain every available species from nurseries and private collectors throughout Britain. Plants were delivered by rail to Arisaig and sent onwards to the garden by road. Each specimen was catalogued with its species name, collector's number, provenance and price. Holms planned the garden and experimented with different methods of shelter necessary to protect young plants from the cold and wind, until they became established. Western hemlock fir (Tsuga heterophylla) was planted to give shelter from the west winds and form glades for specimen Rhododendron. Bamboo and hornbeam hedges were used elsewhere.
The garden took priority. Although Holms started to build a house, it was never finished. Despite the difficulties of travel, accommodation and labour, Holmes assembled one of the largest and finest collections of Rhododendron in an incredibly short time – less than ten years. The catalogue of plants offered for sale from the gardens on his death list 200 species (Catalogue, 1939). He also planted many other species known to thrive in west coast conditions such as Embothrium, Gevuina, Weinmannia, Tricuspidaria, Lomatia, Cunninghamia and Magnolia A prime coup was the first flowering, in April 1933, of Rhododendron sinogrande – one of its first outdoor flowerings in Scotland.
A year after Holms' death, immediately before the outbreak of war, a sale of plants from the garden took place. The carefully-compiled catalogue of 15 closely-printed pages itemised the species Rhododendron and other specimen shrubs. Due to the sale, and thereafter, many of the rhododendrons left Làrach Mòr and found their way to gardens throughout Britain. However, many specimens were left, due either to the wartime conditions or the physical difficulty in removing prime specimen plants.
Holms was assisted by a team of gardeners, a major figure being John Brennan, who remained at Làrach Mòr until his death in 1959. He lived in the gardens, in a small wooden bothy devoid of modern conveniences, and became a well-known character to locals and visitors alike.
Following Brennan's death, the new tenants became aware of the need to manage the regenerating and over-mature woodland, and the decaying drainage system that was threatening the collection's survival by changing the ground conditions. In some areas of the garden the Rhododendrons were becoming engulfed and obscured by scrub. Since the 1960s, a programme of renewal and management has secured the future of this prime collection. A number of specimen trees and shrubs can be directly identified due to the survival of their original lead labels, which relate to Holms' accession books. Most of the labels relating to the Rhododendron, however, have been lost.
The garden continues in the ownership of the Arisaig Estate.