Judges at the RHS National Rhododendron Show, held at RHS Rosemoor in North Devon, presented Head Gardener Gary Long and his team with "The McLaren Challenge Cup" for their Rhododendron arboreum subsp.delavayi var.delavayi. This cup was first awarded in 1932 to George Johnstone, an expert horticulturalist who inherited Trewithen in 1904.

As well as the main rhododendron competition, the show also included the South West Rhododendron, Camellia and Magnolia Show in which Trewithen won twelve prizes.

Gary enlisted the help of Gardener Neil Trebilcock, Trewithen's Plant Centre Manager Marilyn Lawrence and volunteer Lee Hall to prepare and organise the blooms which resulted in a total of thirty awards.

Gary said: "It's the first time Trewithen has entered the show for at least 50 years and to have received so many awards is brilliant. The icing on the cake was winning ‘The McLaren Challenge Cup' for species rhododendron (Class 3). It has made the win a whole lot more pleasurable knowing that we have followed George Johnstone to success.

"The competition was world class with stunning displays most notably from Exbury Gardens, Southampton and Caerhays, St Austell, which made the show probably one of the best floral displays anywhere in the world."