Palm Reading
By Chance Austin-Brecher
Photo: Brian Wintz, Restoration Supervisor
Did you see something a little jarring in the sky this past December? Something slightly disorienting flying by? Maybe you were driving to work, cruising down the 8 somewhere between SDSU and the 15. If you live in Del Cerro or Allied Gardens, maybe you were just walking out your front door to get the morning paper. Perhaps you’re a college freshman who stayed behind for the holidays, taking a walk along the northern end of a deserted campus. If that was you, maybe you saw a helicopter lifting palm trees out of Navajo canyon.
It’s certainly a surreal thing to witness, especially in southern California, where the palm tree has long been an iconic symbol plastered across the region’s developed landscapes. But if you dig a little bit deeper into the local ecology, you’ll start to understand just what’s going on and why, over the course of a single day, upwards of three hundred palms needed to be airlifted out.
The Mexican fan palm (Washingtonia robusta) and Canary Island date palm (Phoenix canariensis) are both highly popular decorative trees that are not native to San Diego, but are still grown, sold, and planted prolifically across the city. They are also extremely invasive. What happens so often with invasive decorative species is that they make their way from your backyard or from sidewalks and medians to the city’s urban green spaces, like Navajo canyon, where they do untold damage to the ecosystem, not to mention the risk they pose to nearby property.
Palms grow very aggressively and very quickly. Mexican fan palms grow about three feet per year and in maturity will reach up to one hundred feet tall. Coupled with the fact that their skirts dry out quickly as they grow and don’t shed naturally, a mature palm is essentially a fuse during San Diego’s dry and hot summer months. Nearby residents of Navajo are well aware of the risk this poses, as there was a massive fire just two years ago. They also suck up huge amounts of water in the canyon’s riparian area, which is a crucial ecosystem for native plants and animals. One of the major concerns of aggressive invasive species is the creation of a monoculture. Because the palm trees take up so much of the limited water supply we receive here in southern California, they easily outcompete native riparian trees and shrubs that contribute to biodiversity and provide habitat and food for birds, mammals, and important pollinating insects. With the palm trees taking up so much space and resources, they become one of the only plants that will grow in the creekbed, meaning our animal friends won’t have the same home they’ve known for generations and generations. Lastly, palms are ineffective in terms of carbon sequestration in comparison to our native trees and shrubs. With the loss of biodiversity caused by overbearing invasive species, like the Mexican fan palm or the Canary Island date palm, we are fighting an uphill battle against climate change.
Why the helicopter? Well in short, palms are extremely dense and heavy and they can take quite a long time to decompose. If they were simply cut down and left in the creekbed, they’d just be clogging water flow during the rainy season, which creates a whole new set of problems for the ecosystem. So to make the removal as efficient and effective as possible, San Diego Canyonlands teamed up with West Coast Arborists to get the job done. Our restoration field team spent nearly a year creating accessible trails to each and every palm that needed to be removed, prepping the palms by removing the dead fronds around the trunk and hauling the material out through the difficult terrain, and finally establishing a buffer zone around the trees to make things as easy as possible for the sawyers of West Coast Arborists to come in and do their job. Once all the trees had been felled, the arborists came back in, securely attached a steel cable to the palms one at a time, and from there, once the helicopter was in position, they safely attached the cable around the tree to the cable on the helicopter. The chopper would then fly gracefully and quickly above the canyon with the gigantic palms in tow and drop them gingerly at the staging area by the canyon’s trailhead, where it would then be loaded onto a truck and driven away. All in all, the whole process for getting one tree out would take less than a minute and all three hundred plus trees were gone within just a day of work.
Hopefully you were able to see it this past December, it was an incredible sight to behold. If you didn’t? Well, there’s plenty more palm trees to be removed across San Diego and still half of Navajo canyon left to tackle, which we plan to do in the near future. Of course you know the old saying: the best time to remove a palm tree was twenty years ago. The second best time is now.