Glenarn, Glenarn Road, Rhu, Helensburgh, G84 8LL

Mike and Sue Thornley had no plans to take over a 12-acre Victorian garden when they were invited to visit Glenarn in 1983, but one glimpse of its spreading magnolias and magnificent specimen trees and they felt compelled to restore it, swapping their small garden in Eaglesham for a project that has occupied them ever since.

Glenarn had been gardened intensively by the Gibson family, who owned it for more than 50 years, but in the decades before the arrival of the Thornleys it had fallen into decline and it took years of endeavour to restore paths, open up views to the Gareloch and bring the garden back to life again.

Today Glenarn is renowned for its collection of Himalayan plants, for its extensive rock garden created in the space from where stone for the house was quarried in the 1840s, and for its vegetable garden bursting with produce. However it is for its rhododendrons that Glenarn is best known.

The Herald: GlenarnGlenarn (Image: free)

The Gibson brothers, Archie and Sandy, who had inherited the house from their father in the 1930s, became friends with some of Scotland’s most important landowners at a time when these were sponsoring expeditions by plant hunters, including George Forrest, and were soon acquiring seed and plants.

Neither Sue nor Mike were rhododendron experts when they started working on the collection but they recognised that the many important species and early hybrids that the garden contained needed proper care if they were to continue to flourish, so they began to propagate these from cuttings and seeds and they also obtained the planting records of the Gibson family, which they have since added to with their own introductions.

This is a good year for rhododendrons, with Mike Thornley attributing the spectacle to recent hot summers that have helped to stimulate flower buds, and visitors to the garden at the moment are greeted by Rhododendron arizelum, which is one of many big leaf rhododendrons that flourish at Glenarn.

The yellow-flowered Rhododendron campylocarpum is one of a number of plants that arrived in 1933 in a tray of small seedlings from Inverewe, while Rhododendron quinquefolium from Japan forms a latticework of branches whose delicate leaves have a dash of purple on their tips matched by the dot of green at the ends of the five white petals of the flower.


Looking to get rid of clegs and midges? Plant some lavender

North Coast 500 things to do - Attadale gardens in Strathcarron

The blowsy, voluptuous Rhododendron Loderi are beginning to scent the garden and another outstanding scented plant is tender Rhododendron lindleyii collected by George Sherriff in 1938. This grows in thickets notably on the edge of the area known as Granny’s Hens, which is the only flat area in the garden.

Also in flower now is Rhododendron falconeri including one giant specimen which has grown at Glenarn for more than 160 years and is said to have been collected by Joseph Hooker in Sikkim in 1848.

On Saturday, 27 April, the Scottish Rhododendron Society is holding its annual show in the Gibson Hall, Garelochead between 12 noon and 3pm, offering visitors the chance to combine this with a visit to the garden. However there is more to Glenarn than rhododendrons, with Anemone nemerosa, trilliums and tulips in spring, perennials in summer and, later in the year, embothriums, crinodendrons and other southern hemisphere shrubs providing lots of colour.

A Silent Space at the top of the garden offers visitors a peaceful spot to contemplate the garden and the Gareloch, while there are also areas of woodland and a pond, once silted-up, but which has been re-excavated and replanted.

The Herald: FalconeriFalconeri (Image: free)

Help in maintaining this historic garden comes from WRAGS (Workers Returning to Agriculture and Gardening), whose trainees work at Glenarn two days a week.

Details: The garden is open daily until 21 September, dawn to dusk.

Tickets: £6/children free Tel: 01436 820493 Glenarn is access from Pier Road in Rhu, which is 27 miles north of Glasgow.

In association with Discover Scottish Gardens