Rhododendron Rebound



Although I’ve never been able to grow them well, rhododendrons have always held a special place in my heart. I grew up visiting the gardens of Cornwall in the school holidays –  Trewidden, Glendurgan, Trengwainton, Lanhydrock, Trelissick and Penjerrick – long before the gates of Heligan and Trebah had swung open. As a small boy I was overwhelmed by the sight of these glamorous grande dames presiding over their fabulous woodland domains, their emerald-green skirts merging together to form dense trains of foliage studded with jewel-like blooms. I would collect the fallen flowers from the mossy ground and stack them on top of one another to create a kaleidoscopic tower of pink, red, purple and white. To me they were too beautiful to be left to rot: I wanted to give them a second chance.


white rhododendron, Sandling Park, May 2016


The practical needs of rhododendrons – their general requirement for acidic soil and generous space – has precluded me from growing these fine shrubs extensively in any of my gardens to date. However, Him Indoors has been briefed that our next home will have several acres of attendant sheltered woodland, situated on a deep bed of acidic leaf litter and watered by springs. I can dream! In the meantime I satisfy my springtime rhododendron craving by visiting the great woodland gardens of the south-east, including The Savill Garden, Hillier Arboretum and Sandling Park, where the photographs in this post were taken this May.


Pink azalea, Sandling Park, May 2016


The genus Rhododendron, which includes the shrubs commonly referred to as azaleas, fell out of favour at about the same time we ended our love affair with dahlias, chrysanthemums, gladioli, conifers and hybrid tea roses. Overgrown and gaudily coloured, they became synonymous with the gloomy shrubberies of commuter belt houses and stuffy National Trust properties. Then, to hammer a final nail in the coffin, along came the black sheep of the family, Rhododendron ponticum. It rampaged through forests, nature reserves and National Parks, displacing precious natives, making a general nuisance of itself. Tarred with the same brush, thousands of rhododendron species and named cultivars seemed doomed to linger in the backwaters of every garden centre in the land, waiting for the day when they would be consigned to the clearance bench or tortured by an inexperienced gardener.


pink rhododendron, Sandling Park, May 2016


Then the fortunes of rhodies, as some fashionable types now refer to them, began to change. It was at about the time that the National Trust started to tackle the restoration of the gardens at Stowe, and when The Lost Gardens of Heligan became unlost, that the tide finally began to turn in their favour. Visitors started to reappraise the these gentle giants, admiring their form, hardiness and myriad flower colours.


Yellow deciduous azalea, Sandling Park, May 2016


Before anyone rushes out to start a rhododendron collection it’s essential to understand what kind of plant you are dealing with. The requirement for an acid growing medium is almost universal and hence a significant limiting factor when most of us cannot naturally offer such conditions.  Cultivation in containers is entirely possible and helped by choosing a compact variety, but watering has to be fastidiously maintained, so rarely is this a long-term solution. In our London garden I grow R. “Sir Charles Butler” in a huge terracotta pot filled with ericaceous compost, sunk into damp ground. Still it requires watering as often as any other pot plant and then with rainwater not tap. Unless you are determined to grow rhododendrons this way, I would not especially recommend it.


orange azalea, Sandling Park, May 2016


Rhododendrons originate principally from the Himalayas where about 600 species can be found. I have been lucky enough to see a handful of them growing wild in India, Nepal and Bhutan. They range from frost tender plants, happy at lower elevations, to large-leaved species growing in conifer forests at around 3000 metres above sea level. As the tree line thins, small-leaved rhododendrons may be found sheltering amongst juniper scrub and alpine meadows, where there may be snow cover for much of the year. In size they range from the diminutive, tropical, tree-hugging vireyas of cool cloud forests to mountaineering, arboreal giants. A few species, such as the Japanese R. yakushimanum are very tolerant, surviving freezing winters and baking hot summers in exposed positions.


red azalea, Sandling Park, May 2016


Over the last century plant breeders have developed more and more exotic hybrids, with about 20,000 currently registered. To celebrate their 100th anniversary, the RHS Rhododendron, Magnolia and Camellia Group (originally The Rhododendron Society), canvassed members from all over the world to compile a list of the top 100 rhododendrons of the century. All of them can be enjoyed in this video presentation, with the top 10 listed below.



The RHS Rhododendron, Camellia & Magnolia Group Top 10 Rhododendrons

  1. R. yakushimanum ‘Koichiro Wada’ AGM
  2. R. macabeanum AGM
  3. R. ‘Loderi King George’ AGM
  4. R. augustinii AGM
  5. R. falconeri AGM
  6. R. cinnabarinum ssp. cinnabarinum
  7. R. bureavii AGM
  8. R. arboreum
  9. R. pachysanthum AGM
  10. R. sinogrande AGM


Mauve azalea, Sandling Park, May 2016


Whether you’re a rhodie roadie or a committed rhododedrophobe I’d love to hear your thoughts on these incredible shrubs. For me, nothing surpasses a woodland garden in May, the dark green hulks of rhododendrons dripping with flowers and the naked stems of deciduous azaleas alight with flaming, scented blooms – My idea of heaven.

Finally, for those of you who have read this far, it’s The Frustrated Gardener’s 4th Birthday today. Thank you to everyone who has been with me on the journey since the beginning or has caught up with my blog along the way.


Yellow deciduous azalea, Sandling Park, May 2016