Riddle of the rowan

Now a common garden tree, its origins are shrouded in mystery. Sorbus 'Joseph Rock' defied classification for decades before becoming one of our most popular small trees

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RHS Gardening Podcast
Episode 113 (item starts at 22:56)

Autumn colour of Sorbus 'Joseph Rock'
The original plant of Sorbus ‘Joseph Rock’ still grows at the foot of Battleston Hill but has seen better days. It is crowded out by other vegetation and has probably not much longer to live. No doubt it will take the precise secrets of its origins with it to the grave.


Rock's house in LijiangFor nearly 30 years the explorer and linguist Joseph Rock (1884 – 1962) collected plant specimens and seeds in Asia. In 1932 he found himself in northwest Yunnan where he was sponsored to hunt plants by the University of California Botanical Garden. Here he made a collection of some Sorbus seed (R23657) that, in a way still veiled in mystery, gave rise to the cultivar ‘Joseph Rock’. The picture shows Rock’s house in Lijiang, northwest Yunnan.

Battleston Hill 1936Battleston Hill shortly after it was purchased from the neighbouring Lovelace Estate in 1936. The original vegetation of the hill was a tangled mixture of brambles, bracken, Scots pine and sweet chestnut (some large specimens of which still survive today).

Little attempt was made to clear the site until after the Second World War so Sorbus ‘Joseph Rock’ must have been one of the first trees to be planted as it features on a list from 1941 of woody plants growing at Wisley.

Photo credit RHS / Lindley Library.

Battleston Hill in the 1940sThe first path to be forged through Battleston Hill was cleared by the Wisley students in the years following the Second World War. It was a task so arduous that the students named the path the Burma Road. Battleston Hill was to be cleared again in a single night 40 years later when it was smashed by the great storm of 1987, necessitating the closing of the area for two years. Fortunately Sorbus ‘Joseph Rock’ was one of the trees that survived the onslaught. Photo credit RHS / Lindley Library.

Berries of Sorbus 'Joseph Rock'

Standard herbarium specimen of Sorbus 'Joseph Rock'The standard specimen of Sorbus ‘Joseph Rock’ was collected in 1976 and is held at the RHS Herbarium at Wisley.

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