Why Eucalyptus Trees Cover the East Bay Hills


(Updated 11/27/16: fixed broken links, changed photo)

During the long summer days, the hills to the east of San Francisco Bay (Alameda and Contra Costa County) are wonderful places to walk — not too hot and with remarkable views to the east, west, and north (until the fog rolls in, and then it’s grey in every direction). The land in the East Bay Hills was originally open grassland with occasional small stands of trees like live oak, madrone, and willow. Most of the year it was “golden”, but after the winter rains the grasslands exploded with the colors of wildflowers among the green grass. Today, however, the hills are covered with eucalyptus trees imported from Australia. So how such a concentration one type of tree come to the hills Berkeley and Oakland? The July-September 2005 issue of Bay Nature had a fascinating story by Bill O’Brien about how it happened. It is a tale of optimism, hard work, greed, and how nature can wreck humanity’s plans.

But first, why should anyone care? While many imported plants behave nicely and stay in the region they are planted, others rapidly expand their range and out compete the natives. The Nature Conservancy’s Invasive Species Initiative says this about non-natives:

Invasive species damage the lands and waters that native plants and animals need to survive. They hurt economies and threaten human well-being.  The estimated damage from invasive species worldwide totals more than $1.4 trillion – five percent of the global economy.

Eucalyptus trees are ecologically problematic and notoriously flammable (they tend to explode when they burn and flaming pieces of bark can be carried long distances by the wind). Stands of eucalyptus tend to be less diverse than native lands, but by no means devoid of natural life. In the Bay Nature article, O’Brien writes that ” A recent study by biologist David Suddjian counted more than 90 bird species that make regular use of Monterey County eucalyptus habitats, including at least 59 species that nest in them. Eucalyptus trees on the shores of San Leandro’s Lake Chabot host a large heron rookery. In Santa Cruz County, Suddjian found that great egrets, great blue herons, and double-crested cormorants nest exclusively in eucalyptus.” And at Ardenwood Historic Farm in the southern East Bay, monarch butterflies use eucalyptus for shelter and sustenance as they over-winter in the Bay Area. The trees are remarkably resilient, so removal of the forests is not easy: chop one down, and the next season the stump be covered with vigorous new shoots.

Haven’s Dream

Almost all of the eucalyptus in the East Bay Regional Park District can be traced to a company founded by Frank Havens (1848-1918). Havens was one of the early builders of Oakland and Berkeley, most notably public transportation and utilities. He was also a partner in the company that built the Claremont Hotel. At various times he worked with Francis “Borax” Smith, who originated the Twenty-mule-team borax product.

Havens founded the People’s Water Company in 1906, with holdings that stretched from Richmond to San Leandro. In 1910, his Mahogany Eucalyptus and Land Company started planting seedlings. Since California had little native hardwood and the population was rapidly growing, Havens’ goal was to create a local source of lumber (and revenue, of course). Eucalyptus was thought to be ideal because it was fast growing and the trees coppice readily (i.e., sprout shoots from a cut stump), thus reducing the need for replanting. Somewhere between one and three million seedlings were planted in the East Bay hills between 1910 and 1914. Havens’ firm also built 9 plant nurseries, a sawmill, and arboretum. During the peak planting season the company employed as many as 200 people.

Havens’ dream died quickly — he shut it down in 1914, just four years after starting the project. Although the trees grew rapidly, they were unsuitable for lumber because they were difficult to plane without chipping and the wood cracked while drying. The article does not give a definitive reason for the failure of the project, but some have theorized that the mild Bay Area climate and lack of natural pests caused the trees to grow too quickly, which led to wood characteristics that were different than those found in Australian trees.

Like many other get rich schemes in California (hydraulic mining, for example), a short burst of activity had long-lasting impacts on the ecosystem, ones that we are still dealing with many decades later.

Additional Resources

Photo Credit

Photo of Juvenile Red-Shouldered Hawk [in Eucalyptus tree] from Margle Savage’s Flickr collection, subject to a Creative Commons License



  1. I once helped coordinate a forestry meeting at Asilomar that had lots of Australian scientists. Multiple times, I heard glowing remarks about how beautiful and unblemished our California eucalyptus trees were (thanks to the lack of natural pests you mentioned)!

  2. It's interesting that you mention the health of CAlifornia eucalyptus trees because over at Save Mount Sutro Forest, commenter Gus – Eucalyptologics sees the California eucalyptus as a gene bank:

    "For the case of Mount Sutro, their historic value may be complemented with a 'hidden' genetic value. Indeed, they could be considered 'genetic repositories' that could allow to 'trace back' the Californian E. globulus landrace to its original race or races in Australia, be it mainland Australia or Tasmania.

    "In other words, they are alive pieces of biological archaeology. Their original parent trees might no longer be standing due to clearing as Australia was built. Mount Sutro trees could be … a lost tribe and the last of their kind."

  3. So informative. We have a eucalyptus tree here in our house and it keeps mosquitos away. =)
    If you wont mind I'd love to guide Foodista readers to your post. Just add the foodista widget to the end of this post so it will appear in the Foodista pages and it's all set, Thanks!

  4. Interesting post! I was not aware of the history of the eucalyptus trees or of their problems before. We're always walking in the Berkeley hills (we just wrote a little post about a hike we often do actually…) I must say, I do love those trees…

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