Last week there was a fire in Stern Grove, in San Francisco. Stern Grove is heavily forested in eucalyptus which did not ignite, providing more evidence that eucalypts are not as flammable as native plant advocates want the public to believe. The claim that eucalypts are highly flammable is one of many arguments native plant advocates use to justify the eradication of eucalypts. And like most of their claims, it is quite simply not true that eucalypts are highly flammable.
The fire in Stern Grove was reported by a local television station. You can view photos and videos of the fire on their website. They report that the fire was started by homeless campers. Nearly 40 firefighters battled the blaze which they described as challenging because it was the middle of the night and visibility was low. The fire moved up a steep hill which has a tendency to accelerate the spread of fire.
This fire in Stern Grove was a particularly rigorous test of the flammability of eucalypts because many of them are shrouded in ivy. The ivy creates a fire ladder to the canopy of the tree, which increases the risk that the tree will ignite. But they did not ignite. The understory of the trees was completely engulfed in flames. The trunks of the trees were badly scorched by the fire in the understory. The fire did not travel up the trees and ignite the canopy.
Let’s talk about ivy
This is an opportunity to talk about the ivy that we find growing up the trunks of the trees in San Francisco. The ivy was planted at some time in the past and in fact, the Recreation & Park Department is still planting ivy when it renovates the parks, believe it or not. It’s a popular groundcover because it thrives with no care and it grows almost anywhere.
Another absurd argument that nativists use to advocate for the destruction of eucalypts in San Francisco is that they are covered in ivy. This seems an extreme case of cutting off your nose to spite your face. Why kill the tree when it’s the ivy that is the problem? It’s not the tree’s fault that it’s covered in ivy. It’s the fault of the Recreation and Park Department that it provides so little maintenance in the parks that the ivy grows out of the control. How does destroying the tree solve the problem? The ivy will overwhelm anything that grows there. Trees aren’t the exclusive target of ivy.
Our personal experience with ivy
We know from personal experience that it’s not that difficult to control ivy. We’ve never planted ivy but we have inherited it in our gardens from previous owners. My spouse complained bitterly about the ivy. But as the primary gardener in the household, I knew we did not have the fortitude to eliminate it. We don’t use pesticides in our garden so without the physical stamina or the resolve to eliminate it, our only option was to manage it. It wasn’t that hard to do. With an annual “haircut” our ivy was never out of control.
We have also had the experience of watching ivy being successfully managed in a public park. In the City of Piedmont’s beautiful parks, ivy is the predominate ground cover. It doesn’t crawl up trees or overwhelm shrubs because it is managed.
Another case of eucalyptus being scapegoated
The eucalypts in San Francisco’s parks are shrouded in ivy because the Recreation and Park Department does almost no maintenance in our parks. Watering and mowing the lawns is about the limit of their maintenance. Why would we expect maintenance to improve just because the trees are destroyed? We certainly haven’t seen any evidence of improved maintenance in the 1,100 acres of “natural areas” in which non-native plants and trees are repeatedly destroyed, native plants are planted and are quickly overwhelmed by foxtails and other non-native weeds.
The money being wasted on these unsuccessful “restorations” would be much better spent maintaining the landscape that exists. It would certainly be less destructive.