21 March – 21 September, dawn – dusk (2025). Admission £6.00, children free.

Glenarn survives as a complete example of a ten-acre garden which spans from 1850 to the present day. There are winding paths through miniature glens under a canopy of oaks and limes, sunlit open spaces, a vegetable garden with beehives, and a rock garden full of surprise and season-long colour. The famous collections of rare and tender rhododendrons and magnolias give way in midsummer to roses rambling through the trees and climbing hydrangeas, followed by the starry white flowers of hoherias and eucryphias to the end of the season. There is a Silent Space at the top of the garden with views over the Gareloch.