THE use of a modern database and mapping technology has prompted National Trust gardeners at Glendurgan in Mawnan Smith to seek out rare rhododendron hybrids with local significance.

Cataloguing and plotting the location of all 5,000 plants in the Helford River valley garden has highlighted that some of the rhododendrons were misidentified in the past and, with the plants now correctly classified, the search is on for those missing from the collection.

Generations of gardeners at Glendurgan have planted rhododendrons for their size, flower colour and scent. Rhododendrons bred by Samuel Smith, head gardener to the Fox family at Penjerrick in the 19th Century, are among the collection at Glendurgan and current garden manager, John Lanyon, and his team are keen to plant more of these rare plants to celebrate the local historic connection.

Flower buds from local gardens have been sent to the special micro-propagation unit at Duchy College Rosewarne, and new plants have been grown and have joined their mature friends at Glendurgan. However, the collection is not yet complete.

John and his team have learnt of Penjerrick rhododendrons in north Wales and as far afield as New Zealand which merit further research.

As well as hybrids grown at Penjerrick, the garden team are keen to add some that were originally bred at another famous local garden, Tremough at Penryn. Here, Victorian head gardener Richard Gill bred varieties with local names such as Beauty of Tremough, Trebah Gem and Glory of Penjerrick. Gill was one of the most famous rhododendron breeders of his time, putting Cornish horticulture on the map and supplying plants to the Royal Botanic Gardens at Kew.

John Lanyon said: “I find it fascinating that these great Victorian head gardeners used the latest innovations and plant sources to come up with these magnificent hybrids. Today we’re using modern technology to map and catalogue them, together with the intriguing process of micro-propagation in a laboratory setting, to ensure their survival.”