Homestead Tree Service

The dangers of pruning
MEXICAN FAN PALMS
 
While a striking tree when peeled and pruned, they can be one of the most dangerous trees to maintain when they grow to above 35 feet. Every year climbers are killed in Southern California when the Mexican Fan palms they are pruning slough, trapping them beneath hundreds of pounds of fronds, suffocating the climber in as little as 20 minutes.
Rury Valdez dies while trimming palm tree - San Diego tree trimming

How does this happen?

Above 30‑35 feet the fibers that hold the frond to the trunk go through a form of abscission. This process separates the frond from the trunk allowing the “bag” or accumulation of dead fronds to slide and fall off the trunk (as seen in the photo to the right). However, below this height, the fronds remain persistent and never fall off. This bag of persistent fronds keeps the non-persistent fronds from falling (this can also be seen in the adjacent palm and is evidenced by the swelling of fronds below the freshly peeled portion of upper trunk). As the climber removes the persistent fronds from the bottom up he comes to the spot where the “loose bag” of non‑persistent fronds no longer has enough support to keep it from falling. It slides down the trunk, trapping and pinning the climber with hundreds of pounds of weight. He cannot breath. If he cannot free himself quickly, he dies of suffocation.

In the lower right photo (a blow up of the left photo) the frond seperation can be seen. These fronds come loose and slip down into the next set of fronds, becoming very compact and resistant to breaking apart and falling off. This “bag” has become a latent trap, waiting until the fronds beneath are removed and then sliding down the trunk.

Mexican Fan Palm - San Diego tree trimming
Mexican Fan Palm closup 1
Mexican Fan Palm closeup 2
The safest way to prune these are with an aerial lift. If access does not permit, there are new and safer techniques than climbing under the bag of dead fronds. Does your tree service have an aerial lift? Does your tree service know how to safely prune these? Do they carry worker's compensation insurance in case of an accident? Or will you be left holding the “bag?”