Updated: Oct 5, 2020
Fan Palm trimming season is upon us, and what better time to talk about - Fan Palms! We see them all over the Vegas Valley, classic icons of our desert oasis, the genus Washingtonia, more commonly known as Mexican and California Fan Palms. These stately trees are able to thrive in our harsh desert environment, without much fuss, and are much beloved by home owner and horticulturalist alike.
Sadly, we also commonly see these misunderstood monocots fall victim to poor pruning and maintenance. These uneducated practices can both cause harm to the tree and extra cost to the customer.
Mexican Fan Palms: Washingtonia Robusta - This palm tree is native to Northwestern Mexico, can grow to 100ft tall, and evidence suggests they may live as long as 500+ years! They're small black fruit is edible.
California or Desert Fan Palm: Washingtonia Filifera - These palms are closely related to the Mexican Fan Palm, though they are generally thicker, shorter, and slower growing. They are also slightly hardier with more flesh on their fruit. Native to the American Southwest, including our own Mojave Desert, these palms are among our country's biggest native trees, and can live 250+ years.
Washingtonia Filibusta is a hybrid of both, possessing mixed characteristics of either species and notable cold tolerance.
From a purely environmentalist perspective, these guys shouldn't be trimmed at all! The yearly layering of dead frond produces what we call a palm's "beard" or "skirt", which protects the tree, keeps it warm through the winter, and provides habitat for all manner of birds, bugs, and critters. The spring flowers are good for pollinators, and the seeds not only provide animals with food, but sprout new trees and continue the cycle.
But trimming is often needed to protect human interests, such as aesthetics, preventing property damage, eliminating fire hazards, keeping surrounding areas and pools clean, preventing falling debris hazards, to keep away pests, and to prevent the invasive sprouting of more palms. Our job as arborists is to find a medium that works for everybody, what is healthy for the tree, and best in our clients interests.
Ideally, fan palms should only be trimmed up to a "9 and 3" position. Removing all dead fronds, any diseased or discolored fronds, and only healthy green below the horizontal line. All cuts should be made cleanly, tight and uniform against the trunk. The palm fronds can be trimmed slightly higher if the client really values the aesthetic, even more to avoid obstacles or mitigate disease. This produces the desired effect, without overly stressing the tree, and leaving it enough vigor to continue to grow happy and healthy. When done at the right time of year - July through September, the seed pods can be removed at the same time to avoid the mess on the ground, and the endless supply of baby palm sprouts.
Constantly throughout the valley we two big problems with the palm tree work that's done: over trimming and poor timing. These repeated hack job procedures border on wanton scamming of clients. Over trimming is stressful on the tree, slowing it's growth and jeopardizing it's health. Repeated over trimming leads to thinner trunks and puts the palm at risk for failure. Shady tree workers and landscapers will push this type of trimming just to get paid, charging the client more for trimming more, and coming back multiple times a year to keep it "cleaned up".
Timing is the other issue. Palms done too early will still shoot out seed pods, which after making their mess will dry up and die, ruining the intended look. Palms trimmed too late will already have dropped there seeds and made their mess. Again, unethical companies will do the work regardless of season (or educating clients), just to get paid. It pains us to see all the trees and people in town being preyed on by butchers.
Timing and Frequency:
The best time to trim fan palms in Las Vegas is between July - September, so the seed pods can be removed at the same time. Seed pods first become visible around May or June, but if trimmed too early the palms will still send out another set of shoots before summer is over. Any later and they will start dropping seeds. Once a year is best for the tree, but if the client is set on keeping a "tighter look", a second round of light trimming can be done in winter. Corrective pruning to get messy palms back in shape can be done throughout the year, with getting them on the right maintenance schedule in mind.
Palm tree skinning is the act of removing the outer layer of bark, or "boots", from the trunk. These boots are the successive remains of trimmed fronds. Palm skinning is done almost purely for aesthetic. It is important to note, that after a certain growth point, old fronds will not hold securely to the trunk. Any dead fronds or boots above that height will flake off on their own (one of the factors that makes climbing taller palms dangerous). Skinning palms too high can be harmful, ample coverage should be left near the top. For tall palms already shedding older layers, this would be what is still holding securely.
The Use of Spikes:
Spikes should be avoided whenever possible. The puncture wounds they produce in the trunk never heal, and expose the palm to pests, rot, and disease. Year after year of
being spiked compounds and does a lot of damage to the trunk. Alternate means of canopy access include ladders, bucket trucks, or rope climbing systems.
If spikes must be used, only on trunks that have not been skinned. The climber should use a ladder or other means to bypass lower sections of trunk that have had the boots removed. An arborist should *NEVER* be attempting to climb with spikes underneath a big beard. Any palms with more than 3 years of dead growth must be trimmed from the top down. Cutting from underneath might cut loose the whole mass, which falls down onto the climber: at best sending your them to the ground, at worst pining them under the weight and suffocating them up in the air - not a good way to go.
Though the process may seem simple and straight forward, climbing and trimming palm trees is one of the most dangerous tasks a Las Vegas tree trimmer faces. This misconception leads a lot of unqualified individuals to attempt the work, with disastrous results. Tree trimming and palm trimming require not only specific horticultural knowledge, but specialized equipment and training to do the work safely. Even professionals within the tree care industry have varying degrees of technical skill and work safety standards. Make sure your climber knows their stuff, and the company prioritizes worker safety.