Our Champion Rhododendrons (Part 1)

In the Growing Leonardslee podcast, General Manager Adam Streeter talks with Head Gardener Jamie Harris about the extraordinary success of the rhododendrons in the historic Grade I Listed gardens.  

This is the latest in the series of podcasts on the challenges of the continuing restoration of the estate, wallabies and wine and everything in between. 

The arrival of spring is a much-anticipated event here at Leonardslee, with its world-famous spring displays. This is particularly so now, with the resurgence of interest in rhododendrons, which have a rich history and are celebrated in various competitions. 

Leonardslee is renowned for its rhododendrons and recently stepped back into the competition scene with its participation in the 2023 RHS Wisley Show. This event showcases a wide range of plants, including early rhododendrons, camellias, and other ornamental plants.  

Although Leonardslee Gardens has a long history of involvement in RHS shows, it has been several decades since the last participation. 

RHS Wisley Winners 

The process of preparing for the rhododendron competition was intense, with the material being cut and stored by Jamie Harris and his team in cool, damp, dark places just days before the show. 

The quick turnaround made for an exhilarating experience, as showcased by Leonardslee Gardens' success in its first attempt – receiving three first prizes, five second prizes, three third prizes, and one highly commended awards. 

Rhododendron competitions not only celebrate the beauty and diversity of these plants but also serve as a reminder of their rich history. The Loder family, previous owners of Leonardslee Gardens, played a significant role in the development and popularisation of rhododendron hybrids. Their legacy lives on as the gardens continue to cultivate and showcase these exquisite plants, even gaining National Collection status for their Loderi and Leonardslee-related hybrids. 

For the RHS Wisley event, the unpredictable weather conditions, characterised by high winds and heavy rains, made it difficult for Jamie and his team to showcase the full range of rhododendrons in their prime. 

In future events, Jamie says he will consider entering camellias, as one of the prizes for these plants is the prestigious Leonardslee Bowl. Donated by Sir Giles Loder during his peak of exhibiting, reclaiming the bowl would be a significant accomplishment for the estate and the gardening team. 

The renewed interest in rhododendrons leads us to explore their rich history and connection with Leonardslee in these podcasts.  

Rhododendrons have become synonymous with Leonardslee due to the significant role the estate has played in cultivating and promoting various hybrids. The legacy left by Sir Edmund Loder and his passion for these vibrant flowers has made Leonardslee a go-to place for rhododendron enthusiasts. 

As a venue, Leonardslee ranks alongside the best sites anywhere, along with the Rhododendron Dell at Kew Gardens, Reuthe's, the lost gardens of Sevenoaks, Lydney Park Spring Gardens, Ness Botanic Garden, Bowood Woodland Gardens, Scotney Castle, and the Isabella Plantation. 

The Legacy of Sir Edmund Loder 

The rhododendron legacy at Leonardslee is deeply rooted in the work of Sir Edmund Loder, who created the Loderi hybrids. These are considered by gardening circles to be among the most important and renowned collections of rhododendron hybrids ever created.  

What makes these hybrids so important, and how did Sir Edmund Loder manage to create the collection?  

The answer lies in the perfect combination of the right plant and the right place. Leonardslee and St. Leonard's Forest provide an ideal environment for growing rhododendrons, with an ericaceous loam and sandstone bedrock creating acidic soil conditions that are perfect for these plants, as well as camellias, magnolias, and conifers. 

The unique landscape of Leonardslee, featuring a bowl-shaped valley, adds to this perfect setting for rhododendron cultivation. The sheltered environment protects the plants from high winds and provides varied levels of shade and sunlight. This, combined with the right soil conditions and aspects, makes Leonardslee a top location for growing these beautiful flowers. 

Adding to the appeal of Leonardslee, the estate is known as one of the finest woodland gardens in the country. This designation comes not only from the informal design and exotic plants interspersed throughout the landscape but also from the grand views, water features, and carpets of bulbs that create a stunning visual display. 

Rhododendrons have been a part of Leonardslee for quite some time, but the estate's history dates back to the 1500s, when it was used by the timber and iron ore industries. The landscape was drastically different, with trees felled for timber and iron ore excavated from the ground, creating the lakes that now form a part of the estate. As the timber industry began to decline, Leonardslee Forest transformed into a rabbit warren, housing up to 12,000 rabbits. 

The Evolution of Leonardslee and its Rhododendrons 

The history of Leonardslee Estate is a fascinating tale of family ownership, gardening, and a passion for plant hunting. Originally, the property was part of the royal family's holdings and was used as a hunting ground. Passed down through various kings and queens, Charles II gifted the estate to Sir Edward Greaves, his physician. By the late 1600s, Leonardslee was in private hands, transitioning through several families until the Loders eventually acquired it, marking the beginning of the estate's renowned rhododendron legacy. 

We can all wonder if the Loder family, known for their interest in plant hunting and bringing new species from abroad, knew they were coming to a perfect place for cultivating rhododendrons. As a local family, they were well aware of the land and soil conditions.  

Before the Loders, the Beauclerk family had already started planting rhododendrons. The oldest rhododendron in the garden, a ‘Cornish Arboreum’, was planted in the Dell area, previously known as the American Garden, and is over 200 years old. 

When Sir Edmund Loder purchased Leonardslee in 1889, his father, Sir Robert Loder, already owned the High Beeches estate. Not long after, Sir Edmund's brother acquired Wakehurst Place. These estates shared many similarities, but Leonardslee's soil and aspect made it doubly perfect for cultivating rhododendrons. 

Rhododendrons can be found on most continents, but the most significant species come from China and the Himalayas. Plant hunters of the early 1900s ventured out to collect plant materials, discovering hardy rhododendrons on mountainsides. These plants were then introduced to gardens like Leonardslee, enhancing the estate's reputation. 

Leonardslee Rhododendrons: Past, Present, and Future 

The story of Leonardslee's rhododendron legacy is not only about discovering new plants but also about creating unique and important hybrids. Sir Edmund Loder played a crucial role in cultivating these hybrids, using the parent plants Rhododendron fortunei (discovered in 1855) and Rhododendron griffithianum (discovered in 1850).  

Sir Edmund began his breeding process in 1901, and within six years, his first cross flowered. Over time, he produced around 35 hybrids, which are regarded as some of the most important ever created. 

Sadly, Sir Edmund passed away in 1920, leaving some of his hybrids yet to flower. However, the Loder family, including his wife, Lady Loder, and grandson, continued the hybridisation process. Rhododendron ‘Leonardslee Primrose’, for instance, was created after Sir Edmund's time, reflecting the ongoing commitment of the Loder family to this remarkable legacy. 

The Loderi hybrids, numbering around 35, are mostly still present in Leonardslee's gardens, and National Collection status has been granted to the estate for its Loderi and Leonardslee-related hybrids.  

Managed by Plant Heritage, the world's leading garden plant conservation and research charity, this status helps preserve essential plant collections for future generations. Out of the 42 hybrids in the collection, 17 can only be found at Leonardslee, with some represented by just a single plant - so it is a very rare and precious garden sanctuary! 

The garden's Grade I Listed status is a testament to the importance of this rhododendron collection. Preserving these living, breathing plants is crucial, as they are more susceptible to changes and challenges. 

In the next podcast, we’ll be looking at the present and future of Leonardslee's rhododendron collection and determining what lies ahead for these magnificent plants.  

We invite you to hear more about the rhododendron legacy in the next podcast. Today, through the present owners, the Streeter family, Leonardslee continues to display the dedication and passion of the Loder family and the ongoing commitment to preserving these stunning plants for generations to come.