The state is full of California palms due to their iconic appearance and low maintenance level, as well as their perfectly adapted state to the local climate. Unfortunately, there is also an array of diseases which have taken to infest our local California palm tree population, most significantly the Pink Rot, Diamond Sale, and the Fusarium Wilt. By informing yourself about these diseases, you will be able to spot the warning signs and know what to expect for the future of your tree.

Pink Rot

The majority of Californian palm trees is susceptible to catching pink rot which is transmitted by a fungus with the catchy name of Nalanthamalavermoeseni. Fortunately, pink rot is often only a serious issue for already weakened trees.You can spot pink rot by keeping an eye on rotting and deformed leaves, and signs of rot along the trunk. However, most commonly, the rot will be limited to the upper portion of the tree’s leaves. There is a chance of recovery for infected trees, but some do find their demise as a result.Preventative measures include general tree care, i.e. not damaging the roots, watering them during droughts, and pruning them according to their species’ recommended frequency.

Diamond Scale

A fungus by the name of Phaeochoropsisneowashingtoniae is responsible for infecting trees with diamond scale. While this disease rarely leads to a tree’s death, it is also far from pretty to look at, and it can make your tree susceptible to other infections which could lead to its demise.You can spot this disease by taking note of darkened spotting on your tree’s leaves which then transform into mushroom looking growths the shape of diamonds. Over time, the infected leaves will start to brown until they eventually die completely.

Fusarium Wilt

Brought on by the Fusarium oxysporum fungus, fusarium wilt in California generally refers to canariensis, which is a form of the fungus that specifically attacks the Canary Island palms, and causes their leaves to brown and then wilt, and the tree to weaken. As a result, the palms will become highly susceptible to other diseases which oftentimes cause them to die before the fusarium wilt can get the job done itself.

How An Arborist Can Help You

Whether you are looking for answers in regards to your tree’s health, or which tree is best befitting to your specific needs, your best chance at obtaining the information you require is to call a certified arborist in Bay Area. They understand all aspects of the issues that your trees are facing and will evaluate the situation and give comprehensive treatment. This will not only keep the trees healthy but adds to the curb appeal of your home.


Anyone who really cares about their trees knows how hard it is to find a good tree trimmer. I’ve used both major name brands, and self employed tree trimmers, and have never been very satisfied, until now. ArborWorks trimmed my trees as carefully as I would have, if I knew how to climb trees!Don McIntyre, owner, responded within two days of my call, and his estimate was fair and thorough. He personally brought the foreman of the crew to my site to go over the job the evening before the crew would actually arrive. Don also visits the site as the work is performed, to make sure everything goes smoothly.If my trees could vocalize, they’d sing about the space created for light to enter the crown, and how good it feels to have the weight off the ends of the limbs. Even neighbors have come by to complement me on how good the trees look. “Best ever”.I only wish I had known about ArborWorks sooner. It took me 32 years to find them. I hope my trees will forgive me for taking so long…
Karen K. Mountain View, CA


Arborworks Inc. Diamond Certified