We use the word “natural” frequently, but just what it means is often a cause for debate. Here’s a local example.


We all recognize eucalyptus trees.  In many places, including numerous locations in Tulare County, they dominate the California landscape.  Some eucalyptus species (notably blue gums) grow large, and trees six or eight feet in diameter and 150 feet high can be found.


In many places in California, including here, eucalypti reproduce without human help, and over time they can establish permanent groves and even forests. That leads us to a question:  Should we consider these trees to be “natural” in California?  


I’ve just outlined the argument that suggests a positive answer to this inquiry. Eucalypts (yet another name for this genus of trees) grow well in California, reproduce without human assistance, and are so common that they have come to define the appearance of many rural landscapes.


The argument against takes a different track. Eucalypti are not “natural” in California because they are not native plants. Instead, they are imports from across the Pacific Ocean. All the many forms of eucalypts that grow in California today are descendants of Australian plants brought here mostly in the late nineteenth century for industrial and horticultural purposes.


The importation of eucalyptus into California profoundly changed the appearance of the Golden State.  Many hoped that the large fast growing types, trees like the blue gum, would become a major source of lumber. Lands owners established eucalyptus forest plantations with the expectation that they would be able to harvest and sell their timber.


Most of these plantations ultimately disappointed their owners. Gum trees, it turned out, produced a twisted and crack-prone wood that did not saw well into construction timber or railroad ties.  But even while they failed as a source of lumber, the trees soon displayed other values.


Farmers found that water-thrifty eucalypti could be used to create effective windbreaks along the margins of fields.  Older readers will recall miles of such windbreaks defining the edges of fields in the Salinas Valley and around the extensive Southern California citrus groves that existed for a century east of Los Angeles in Riverside and San Bernardino counties.


The trees also became popular ornamentals – huge defining garden elements around which a landscape could be organized. Many ranches planted the trees for shade, and hundreds of miles of California highways were planted in long rows of gum trees.


Today, eucalyptus trees, or at least the larger types, have fallen out of favor.  Over time we came to realize that these fast-growing trees were messy, sometimes dangerous, and highly fire-prone. Yet, the trees still grow happily almost anywhere you look in the lowland parts of Central California.


Locally, some of the best remnants of the California eucalyptus boom can be found around Goshen.  The KOA campground there on the west side of Highway 99 occupies the remnants of a eucalyptus plantation. The tract stands immediately adjacent to the old railroad junction at Goshen, where long ago the Southern Pacific and Central Pacific railroads exchanged traffic. I have long wondered if the railroad companies planted this grove.


North of Goshen along Highway 99 one can see some of the last of the big eucalypti that once lined so many miles of old U.S. Highway 99.  The recent road widening there took out some of these trees, but the project purposely protected some of these stately reminders of what many California highways looked like in the first half of the twentieth century. 


Downtown Visalia long had its own historic eucalyptus tree.   Planted by David Douglass in 1860, the tree stood for 128 years before it finally came down in 1988.  Its site is still marked within what are now the grounds of the Visalia Convention Center.


So what are we to make of our eucalypts?  Unlike our valley oaks, these impressive trees cannot be called “native,” but does that make them “unnatural?”  Perhaps, like most of the rest of us, they can best be described as “naturalized” – organisms that have found themselves well adapted to California and established permanent residence.


Eucalyptus trees visually define our valley landscapes. They tell us that we are on familiar ground.  As long as we are here, they likely will be too.


© Wm. Tweed