Even though they are not native plants, palm trees are among the most recognizable elements of the Los Angeles landscape and a bit of a symbol of what it represents. Most of those seen today in the city were planted between the end of the 19th and the beginning of the 20th century, but now that many of them are dying due to old age or disease, the local administration is considering do not replace them with new palm trees. Los Angeles is one of the most polluted cities of the United States and its average temperature is expected to continue to increase in the coming decades: however, palm trees are not as efficient as other plants in alleviating the effects of global warming produced by human activities.
In California there is only one type of palm tree nativethe Washingtonia filifera, while most of the tens of thousands filmed in films set in Los Angeles or printed on postcards are of other species. Non-native palms were brought to California by Spanish Franciscan missionaries at the end of the eighteenth century and spread from the end of the nineteenth century, mostly for ornamental purposes. As Donald Hodel, former horticulture and landscaping consultant at the University of California, observed, with their appearance «exotic, theatrical and tropical» they served to attract inhabitants from other parts of the United States in a period of great development, favored above all by Hollywood. Only in 1931 were they planted 25 miles to beautify the city for the following year’s Olympics.
Over time, palm trees transformed a natural landscape that had previously been predominantly arid and desert-like, and characterized the city’s most famous neighborhoods and avenues, from Venice Beach to Beverly Hills to Sunset Boulevard. At the same time, their presence contributed to defining the idea that Los Angeles was a warm and welcoming, rich and prosperous place: in short, palm trees became part of the cultural identity of the city, as well as important resources also for tourism and therefore for local economy.
Recently the number of palm trees in Los Angeles it dropped: many (it is not clear how many) died due to old age, or due to a beetle-like parasite and a fungus that are lethal to that type of plant. Hodel estimated that several of those planted for the 1932 Olympics could still survive for between thirty and fifty years (some species live up to 150), but in general he defined them as “retired”. Given the need to increasingly exploit green areas to have more shade and combat heat and pollution, however, the local administration plans to replace them with other plants.
Los Angeles in a photo from circa 1940 (Hulton Archive/ Getty Images)
The type of palm most widespread in Los Angeles County is the Washingtonia robusta, which is typical of the north-west of Mexico, can grow up to 25-30 meters in height and has a foliage with leaves even more than 5 meters long. However, to grow it needs large quantities of water and provides very little shade, at least when compared with trees such as oak or ficus typical of California. In the words of V. Kelly Turner, a geography and urban planning researcher at UCLA, palm trees don’t do much in the way of heat mitigation during the heat of summer: “A pole on the side of the road doesn’t provide much shade. A palm tree is a bit the same.” Plus, they don’t help absorb significant amounts of carbon dioxidei.e. the main greenhouse gas responsible for global warming.
Average summer temperatures in California have increased by around 1.8°C since 1896, and it is estimated that by 2040 they will be more than 2°C higher than in the pre-industrial period. In these circumstances according to experts it will be necessary among other things, investing in the protection of forests and the development of urban green areas, in particular by planting plants that are on the one hand able to resist the climate crisis and drought, and on the other to refresh the environment, improving quality air and making neighborhoods more livable. Los Angeles has already partly taken action in this direction.
(AP Photo/ Jae C. Hong)
The city’s environment department has made it clear that in its program to plant new trees are not included the palm trees. Not even the Department of Forestry and Fire Protection allows the winners of its tenders to plant palm trees because they require a lot of maintenance and do not bring many benefits: “The cost-benefit ratio is not positive,” he told the Los Angeles Times the head of the department, Walter Passmore.
The Beverly Hills Urban Green Management Plan, prepared by the Dudek firm, recommends that palm trees that have no historical significance or provide tourism benefits be “evaluated and selected for removal and replacement with trees that provide more shade.” ». Among other things, the Los Angeles Department of Forestry Sciences has made it known that it is collaborating with other administration offices to understand how to create more space to replace the palm trees with trees that provide more shade and are possibly native.
As he said to Los Angeles Times arborist Ryan Allen, among the Dudek experts who contributed to assessing the city’s conditions, “between a palm tree or a shade plant, planting a palm tree is like missing out on opportunities.”
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However, it is unlikely that the landscape of Los Angeles will undergo major upheavals, at least for the foreseeable future.
Il Los Angeles Times maintains that palm trees will probably continue to exist in the city for a long time, both because it is likely that people will continue to plant them on private properties, and because some neighborhoods are replacing some of the dead ones with other palms for reasons of landscape uniformity. Elizabeth Skrzat, the director of the local government’s program for planting new trees (City Plants), also doubt “I’m serious about the fact that palm trees will disappear completely.” According to Jared Farmer, history professor and author of the book Trees in Paradise“the great palm tree die-off” in Los Angeles could instead become one of the typical dystopian stories of Hollywood cinema: “an American experiment gone wrong”.