Although the orange and the palm loom large in Southern California's iconography, another imported tree – the eucalyptus – has been almost as prominent a feature of the region's landscape. Eucalypti grace parks and gardens and shade sidewalks and roadways. In many suburbs, long rows of the tree, planted long ago as windbreaks, betray the land's past use for citriculture.

How did this tree, an invader from an alien botanical world, come to tower over so much of the region's streets and green spaces?

But prior to the 1850s, not a single eucalyptus grew in California, which raises the question: how did this tree, an invader from an alien botanical world, come to tower over so much of the region's streets and green spaces? Who eucalyptized Southern California?

Eucalyptus leaves, flowers, and the opercula that give the genus its name. Courtesy of the USC Libraries – California Historical Society Collection.

Native to Australia, eucalypts feature leathery leaves and flowers whose petals fuse together to form a cap. In fact, the name of the tree's genus, eucalyptus, refers to this bud, deriving from Greek words meaning "well-covered." Botanists recognize more than 500 distinct species, but California is best acquainted with one: eucalyptus globulus, also known as the blue gum. Eucalyptus globulus, indigenous to Tasmania and southeastern Australia, is instantly recognizable by its minty scent, shimmering leaves, and peeling bark.

Historical accounts vary, but according to tradition the first blue gums arrived in Southern California in 1865, when fur trapper-turned-farmer William Wolfskill planted five specimens outside his house – the Hugo Reid Adobe – on Rancho Santa Anita. An agricultural experimenter who made a fortune growing oranges, walnuts, and wine grapes, Wolfskill must have recognized the eucalyptus' potential to upset the commercial timber market; although conifers grew in the mountains, the lowlands of Southern California were mostly treeless plains, broken by isolated copses of live oak and sycamore. The fast-growing eucalyptus could provide a large, local supply of timber in short order.

Wolfskill never saw his experiment through to its conclusion; though. He sold the ranch in 1872 to Harris Newmark, who later sold it to Elias Jackson "Lucky" Baldwin. (Fittingly, although the original eucalyptus trees no longer shade the historic adobe, Wolfskill's homestead is today part of the Los Angeles County Arboretum.)

Southern California's first eucalypti, planted in 1865 by William Wolfskill, line the path to the Hugo Reid Adobe in this circa 1920 photo. Courtesy of the Arcadia History Collection, Arcadia Public Library.

Another view of Wolfskill's eucalyptus trees. Courtesy of the Photo Collection – Los Angeles Public Library.

Instead, others championed the tree. Ellwood Cooper planted a 200-acre eucalyptus grove near Santa Barbara in 1872. Cooper's "Forest Culture and Eucalyptus Trees," published in 1876, became the standard guidebook for eucalyptus cultivation. Another admirer, Alexander Campbell-Johnston of Garvanza (today part of Highland Park), planted tens of thousands of seedlings and wrote extensively about the eucalyptus' virtues, and in 1875 Robert M. Widney's Forest Grove Association planted a 200-acre grove near Downey.

In addition to founding Venice of America, Abbot Kinney championed the euclayptus tree. Courtesy of the Photo Collection – Los Angeles Public Library.

Encouraged by the trees' boosters, farmers planted eucalypti as windbreaks, and the Southern Pacific briefly (and unsuccessfully) experimented with using eucalyptus wood for its rail ties.

But it was tobacco heir Abbot Kinney who turned a regional fad into a landscape-altering phenomenon. Better known today as the developer of Venice, Kinney served as state forester from 1886 to 1888 and used the position to promote the eucalyptus, distributing free seeds across the state. In 1887, he established a forestry station in Rustic Canyon, near Santa Monica, where he planted numerous species of eucalypti, and in 1895 published a 300-page book about the tree.

Kinney's tome extolled the eucalyptus' virtues as a multi-purpose plant. The tree was well-suited as an ornamental tree or as a windbreak, he wrote, but nearly every part of the plant could also be exploited commercially. Eucalyptus oil, for instance, had powerful antiseptic and anti-malarial properties, he claimed. Today, it's a common ingredient in cough syrup.

The eucalyptus could also transform Southern California's treeless landscape in almost an instant:

The introduction of this tree has done more to change radically the appearance of wide ranges of country in California than any other one thing. In the reclamation of many arid plains of the central and southern parts of California the blue gum has worked almost like magic. It modifies the winds, breaks the lines of view all so quickly that one can scarcely realize that a valley of clustered woods and lines of trees was but a year or two before a brown parched expanse of shadeless summer dust.

In fact, many developers had already learned that the blue gum, which can grow as high as 60 feet in only six years, could quickly overcome the oppressive flatness of new suburban towns. A tree outside the Howard & Smith flower shop at Olive and 9th streets in Los Angeles attained a height of 134 feet before succumbing to a windstorm in 1915.

A boy stands in one of the eucalyptus groves at Kinney's Santa Monica forestry station. Courtesy of the USC Libraries – California Historical Society Collection.

Two freakishly tall eucalyptus trees. On the left is a gum tree at Olive and 9th that measured 134 feet before a windstorm toppled it in 1915. On the right is a tree that once grew at the corner of 36th and University (now Trousdale), the present-day site of USC's Tommy Trojan statue. Both photos courtesy of the USC Libraries – California Historical Society Collection.

Two men demonstrate the girth of a 25-year-old eucalytpus tree on the L. J. Rose ranch in Rosemead, circa 1900. Courtesy of the USC Libraries – California Historical Society Collection.

Kinney's advocacy sparked a new wave of interest in the tree that, fueled by a 1907 U.S. Forest Service warning about a shortage of Appalachian hardwood, soon grew into a speculative bubble in eucalyptus timber. Fantastical rumors of 500-foot eucalypti were repeated as fact. Visions of eucalyptus houses, furniture, telephone poles, and wagons – not to mention immense profits – abounded.

Over the next six years, optimistic farmers planted millions of individual blue gums throughout California; a few months in 1909 alone saw the creation of more than 23,000 acres of new eucalyptus groves. Some farmers even replaced productive fields of vegetable crops with eucalyptus stands, and the Los Angeles Board of Water Commissioners mooted a proposal to plant 25 million trees along the Owens River Aqueduct, then under construction.

The bubble soon burst, however, when a 1913 U.S. Department of Agriculture report confirmed what others had long known: that eucalyptus wood warped, cracked, and twisted as it dried. Investors were ruined, and eucalyptus groves reverted to farmland as steel, concrete, and other artificial materials made up for the hardwood shortage.

Although its future as a cash crop was over, the eucalyptus survived the boom's collapse. Many Southern California landscapers embraced it as an ornamental tree, while farmers and orange growers planted endless miles of eucalypti to protect their crops from the wind. Although concerns about the tree's safety cloud its future – its heavy falling limbs are known to be fatal, while in a fire its oil-rich crowns can become explosive – the eucalyptus remains a fixture of Southern California's arboreal architecture.

This massive eucalyptus, pictured in 1928, once grew on Preuss Rd. near Beverly Hills. It became a cause célèbre when real estate interests proposed to cut it down. Courtesy of the Herald-Examiner Collection – Los Angeles Public Library.

Eucalypti and palms in Santa Monica's Palisades Park. Courtesy of the Postcards of California, Oregon, and Washington Collection, Bancroft Library, UC Berkeley.

Eucalyptus trees form a barricade against the wind on an Anaheim farm, 1961. Courtesy of the Orange County Archives.

A eucalytpus windbreak lines U.S. Highway 60 in Riverside, 1938. Courtesy of the Frasher Foto Postcard Collection, Pomona Public Library.

A eucalyptus windbreak gives way to suburban expansion in Orange County, circa 1950s. Courtesy of the Orange County Archives.

Further Reading

Esau, Erika. Images of the Pacific Rim: Australia and California, 1850-1935. Sydney, Australia: Power Publications, 2010.

Farmer, Jared. Trees in Paradise: A California History. New York: W. W. Norton, 2013.