Eric Hupperts, Horticulturist
Rhododendron arboreum
Rhododendron spinuliferum
Up in the Berkeley hills, the Asian temperate forest at the UC Botanical Garden is beginning its spring awakening. Amongst the Magnolia and Camellia blooms is another iconic genus: Rhododendron. This speciose genus has a storied past here at the Garden and includes many of the earliest Garden accessions. In fact, the Rhododendron collection is regarded as one of the more significant amongst the world’s botanical gardens.
Found throughout the northern hemisphere, rhododendrons are exceptionally diverse in Asia. There they grow in a range of habitats, from tropical wet forests to alpine locales with chilly winters. This is especially true in the eastern Himalayan mountains, where ideal growing conditions are reflected in the incredible diversity of rhododendrons.
Early in our spring season here in Berkeley, we have three prominent species blooming, setting the stage for what is to come as the season progresses. Near the Japanese pond grow two Rhododendron protistum, a large-leaved species that coolly displays its immense pink flowers in trusses like floating tiered cakes dancing in the mid-canopy. Ours were grown from seed collected in Yunnan, China, in 1924.
Just a leap across the creek is a grove of Rhododendron arboreum, a wide-ranging species that includes subspecies in the Western Ghats in south India and in the highlands of Sri Lanka. This species is true to its name, growing tall and strong into the canopy. It is the emblematic rhododendron, in fact, it is in the logo of the Garden. This species blooms early in the season, showcasing its deep red-hued flowers.
Another red flowering rhododendron that is now blooming, is our Rhododendron spinuliferum. Its flowers have a much different appearance: upright and tubular, unusual for this genus. This shrub is now at least 86 years old and continues to push hundreds of flowers in its quest for glory.
These three species are just a small part of the incredible Rhododendron collection at the Garden; a collection that began in 1932 and continues to grow and bloom today. On your next visit swing by the Asian Area to witness these incredible botanical legacies.