Eucalyptus: Beauty or Beast?

Restoration pits these exotics against California natives. But for some, they’re a natural.

  • Eucalyptus trees reflect in the canal at the Sweet Springs Nature Preserve.

    Sean Arbabi/
  • A great egret in a pond surrounded by Tasmanian blue gum at the Morro Coast Audubon Society Sweet Springs Nature Preserve.

    Thomas Nash
  • "Eucalyptus trees, oak trees, redwood trees, they're all trees, and trees are good. They are now part of our ecosystem and causing us to redefine the word 'native,'" says Joey Racano, a Los Osos environmental activist.

    Thomas Nash
  • A detail of the blue gum's colorful bark.

    Thomas Nash
  • "It's simply different values, and it's hard to say what's absolutely right and what's absolutely wrong," says David Chipping, California Native Plant Society president.

    Thomas Nash
  • Mature stand of blue gum eucalyptus in California's Presidio of San Francisco.

    Thomas Nash
  • The outward march of eucalyptus from a former plantation has occurred at the rate of about two feet a year. "And over the course of seven decades, that will take you somewhere," says Matt Ritter, botany professor, Cal Poly, standing by a giant old karri eucalyptus at the UC Santa Cruz Arboretum.

    Thomas Nash
  • Volunteers removing invasive veldt grass from native plantings area. Morro Coast Audubon Society Sweet Springs Nature Preserve.

    Thomas Nash

On a Saturday morning in early September, the Sweet Springs Nature Preserve in Los Osos, Calif., bustles with activity. To the east, a dozen or so volunteers struggle to stem the tide of veldt grass that laps at the feet of waist-high lupines. To the west, a great egret stalks the shallows of a small pond, and a few dog-walkers meander along a trail shaded by a lacy canopy of towering Tasmanian blue gums, a type of eucalyptus tree.

Invisible but no less real is the cultural fault line that runs through this preserve, which is managed by the Morro Coast Audubon Society. On one side stand those who would remove some of the blue gums to restore an embattled native ecosystem; on the other are those who believe these tall exotic trees have as much right to exist as the indigenous redwoods, California's official state tree.

As environmental clashes go, this one seems fairly minor, even inconsequential. At issue is the fate of perhaps a hundred blue gums out of the more than 450 that presently grow on the 32-acre preserve, whose springs feed the Morro Bay estuary. Yet the dispute affords insight into a much wider conflict that affects the entire California coast, one that springs from different visions of the natural world and the place of non-native species in it.

Strikingly, the combatants on both sides consider themselves environmentalists, so that beneath the fraught rhetoric lie concerns that are not easy to dismiss. Both seem to share a passionate love for nature, but disagree about which organisms deserve priority. The raptors that sometimes nest in the blue gums and the monarch butterflies that use them for winter shelter? Or the Morro blue butterfly and the myriad less charismatic creatures that thrive amid native grasses and wildflowers?

The trees are problematic for a number of reasons. They grow so fast that their branch structure often gets out of whack; left unmanaged, they tend to lose large limbs, posing a danger to people and property. They drop so much bark and leaf litter and commandeer so much water and light that only the most robust, shade-tolerant natives can grow alongside them. Blue gums can also be invasive. Given access to year-round moisture, they readily spread beyond where they were originally planted. At Sweet Springs, preserve manager Holly Sletteland regularly pulls out the blue gum "volunteers" that sprout amid native shrubs and perennials.

And that's not all. Eucalyptus stands can pose a serious fire danger, as became apparent in 1991 when blue gums burst into flames that lit up the Oakland Hills. While these non-native trees hardly bear all the blame – tinder-dry grasslands, native scrub and Monterey pines also contributed to the firestorm – the fuel load provided by eucalyptus debris unquestionably intensified the blaze. In the span of 72 hours, 25 people died, and well over 3,000 houses and apartments were destroyed.

Yet these same trees, with their shaggy bark and spicy fragrance, are beloved by many. In the blue gum's immigrant history, people see an experience that parallels their own, observes environmental historian Jared Farmer, author of Trees in Paradise: A California History. "There are still a significant number of Californians who are the first generation in the state. They have come to love California. They have come to think of it as home. And they feel this kinship with the eucalyptus. They say to themselves, 'This tree is not from here, but it's beautiful, and it seems to fit.' "

robert shanbrom
robert shanbrom
Dec 31, 2013 03:29 PM
There are tens of thousands of acres of eucalyptus in California. Sweet Springs is a unique habitat of a handful of acres that deserves to be returned to its primordial state of coastal sage, Morro blue butterfly and Morro Bay kangaroo rat rather than eucalyptus, Monarch butterflies and an overpopulation of raptors.
Albyn Jones
Albyn Jones Subscriber
Jan 07, 2014 07:14 PM
Sorry, eucalyptus trees are a noxious weed. They are a real fire hazard, not to mention the hazards of falling limbs and whole trees.
John C Schuyler
John C Schuyler Subscriber
Jan 13, 2014 05:22 PM
If you think of a spectrum of our most pristine lands (e.g., wilderness) to our most developed land (e.g., urban), eucalyptus trees should only be allowed at the urban end of the spectrum. Thus, public lands and parks, lands identified for conservation (either primarily or secondarily), and other wildlands should be free of non-native invasives, including the eucalyptus.
Carolyn Hopper
Carolyn Hopper
Mar 03, 2014 03:21 PM
A list of all the plants carried to this country from immigrants might be helpful to peruse. At the same time study all the land use by all the people here from coast to coast before Europeans and Asians arrived with any plant material. Then look at what is happening to all rivers where non native fish were planted--Rainbow trout comes to mind as just one. Then study all the work being done here in Montana and Wyoming with the eradication of all non-native fish from a few rivers in order to reintroduce a native species. After all that study it might be seen just how complicated eradication of plant or animal species is as it relates to reintroduction of "native" species, especially when an arbitrary date is set for consideration. The prairies were plowed under. Can we eliminate all farm land? Bring back all the milkweed needed by Monarch butterflies who, at this point, are severely reduced in numbers. "Conservation" as a term varies widely as it is interpreted. Chucking Monarch butterflies doesn't seem to be the answer. At the end of the day we as humans have a narrow view of the whole planet and all the ways we have manipulated, stripped, bombed, and lit it on fire--and long term effects of all our actions. Perhaps some things are just going to change and loving or hating a tree shouldn't make the top of the list of what is most important.
How about working as hard for peace as a world, instead of war?
sean mitchell
sean mitchell
Apr 02, 2014 05:34 AM
About 'Gum Trees and other exotics,I'm an amateur (big time) re flora and fauna, but there are exotics that appear to be non invasive,my understanding is they can only be spread by people and even then seem to be benign to the local environment and are a delight to be near,eg Poinciana,Poinsettia,Jacaranda,Frangipani(These are introduced to my part of the world) .Point is, there are lots of Eucalyptus that shouldn't be where they are,(Florida and Paperbarks) if they are not controllable and hence in any way a threat to the way the place was before Europeans waltzed in then best mulch them .
prc food
prc food
Apr 23, 2014 03:51 PM
"Perhaps some things are just going to change ans loving or hating a tree shouldn't make the list of what is most important."

I do love the eucs, and am extremely appreciative of the oxygen they make, the mosquitoes and fleas they repel, the medicinal use of their leaves, the erosion control, the air purifying, the cooling shade.

But the question should be asked, "Are you native?" These trees may have been on this continent longer than you have, they are a carbon sink and part of the solution for global warming, are you?

Native plants are beautiful, and all plants are native to this planet, just like us.