About the genus
Dudleya was named in honour of Professor William Russel Dudley (1849–1911), the first head of botany at Stanford University. Although the earliest species was described by Haworth in 1803 as Cotyledon caespitosa, it was not until a hundred years and several name changes later that the genus was erected in 1903 by Britton and Rose as part of their revision of the North American Crassulaceae.
Despite the fact that Dudleya have been recorded to grow for several decades, their common name of ‘live forever’ relates to their longevity in a different way: in the late 1800s Scottish botanists were apparently amazed to discover that pressed herbarium specimens miraculously survived ocean voyages back to Britain.
There are around 49 Dudleya taxa which range from Oregon, down to California, a brief foray east into Nevada, Utah and Arizona of the United States, and over the border into Baja California. Some dudleyas are also endemic to California’s Channel Islands and Baja’s coastal islands.
How to grow them
Dudleyas are winter growers, having evolved in the winter rainfall Mediterranean climate of western North America. They come into growth in habitat around late autumn, triggered by the rise in precipitation and colder nights. As such, they can bring real interest to the growing space when many popular succulent genera are bedding in for the winter.
The majority of taxa grow along coastal bluffs and mountainous regions, so prefer an extra gritty mix of your favourite growing medium. They benefit from as much light as possible and enjoy regular weak feeds between the growing months of October to May. As days lengthen in the northern hemisphere, the plants will reward you with inflorescences that can grow up to a metre tall and are characterised by a multitude of brilliant colours. Dudleyas are quite cold tolerant and require no extra heat above around 5°C in winter, but excellent ventilation or air movement is advised to reduce stagnant, humid air and the risk of mould.
Be prepared for summer dormancy, where many species dry up to the point of looking like they are barely alive (some even disappear below ground and exist as subterranean, tuber-like structures). Dudleyas also leave their old, dried leaves behind each year. In the heat of the summer, they may be given a drop of water so that their roots do not dry up too much, but not to the point where they are induced into unwanted growth.
Unlike many other members of the Crassulaceae, Dudleya can rarely be propagated from leaf cuttings. However, calloused vegetative cuttings root readily in damp, gritty compost or molar clay. Dudleya seed is dust-like and is incredibly easy to grow. Whilst all Dudleya taxa are self-fertile they are extremely promiscuous, so plants and seed of reliable parentage are hard to source, particularly in Europe.
The most popular species are those that have farinose, white leaves such as D. pachyphytum and D. brittonii (which has the highest measured ultraviolet reflectivity of any plant on earth), but green-coloured forms are also attractive. Many dudleyas are rosette-forming, but there are an equal number that have round, finger-like or spoon-shaped leaves like D. virens and D. edulis, which are similarly rewarding to grow.
Text and photos by Simon Snowden
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