Beware the Australian Silk Oak

The author appears to be already scratching during the removal.
Photo by Gabriell McGinnis of T Town Tree Service.

I am writing to report on an unusual accident that happened to me on the job here in Arizona. I own/operate a tree and landscape service I founded in 2015 and am a professional tree climber.

On June 4, 2020, I removed an Australian silk oak tree (Grevillea robusta) from a residential backyard in Oro Valley, Ariz. I spent maybe 30 minutes climbing the tree and another 10 minutes bucking up the spar on the ground. The following day I started experiencing a red, itchy rash covering my chest, arms and neck areas. This quickly spread to my legs and back and was extremely painful!

The author’s rash cost him five days of missed work and a lot of anguish. Photo by Gabriell McGinnis of T Town Tree Service.

After speaking with different doctors, I eventually ended up with a prescription for 250 mg of diphenhydramine (antihistamine) and 60 mg of prednisone (corticosteroid) per day, along with topical hydrocortisone, lidocaine and calamine ointments to aid with the skin irritation. I missed five days of work and finally got back to light duty/office management six days after exposure.

The author’s rash. Photo by Gabriell McGinnis of T Town Tree Service.

A consulting arborist, Jacquelyne Lyle, Certified Arborist and a docent at the University of Arizona campus arboretum, helped me identify this tree, which I was not previously familiar with, as it is not commonly planted in the Sonoran desert region. I know of a few specimens in Tucson. Lyle said she knows of maybe 10 of these trees in Tucson.

These trees do not reach their “full potential” in this climate. As is often the case with non-native shade trees grown here in the Sonoran desert, you can expect shortened life spans and dwarf-like growth.

The Australian silk oak, Grevillea robusta, prior to removal. Photo by the homeowner, Nicholas Armstrong.

On doing a little research, I found incident reports from Australia and New Zealand where woodworkers and arborists had experienced similar acute contact dermatitis symptoms after exposure to the sawdust of this tree. These symptoms can, in some cases, last two to three weeks.

Gabriell McGinnis of T Town Tree Service, who took some of the accompanying photos, was working for me on the ground that day. He did not have any allergic reaction to the tree, but also was not running a saw that day.

Just to follow up on my condition, it did clear up about a week after exposure and taking the prescribed medications. I feel fortunate I didn’t have to stay on the medication longer, and, of course, am stoked that the nasty rash is long gone! I will not be cutting a Grevillia robusta again! I for one am glad I didn’t scratch myself to death, and am happy to be getting back to any capacity of work so soon. Stay safe.

Victor Riquelme is the owner/operator of Big Olive’s Property Maintenance/Big Olive’s, LLC, in Tucson, Arizona.


  1. Thank you for the information! I was thinking a purchasing one of these trees but now have decied against it since I maintain all my trees myself, and never with as much clothing has you had on!

  2. Hello. So sorry to hear you went thru that. Thank you for the cautionary tale. We just purchased a house in central CA with two silky oaks in the back yard. We had no idea what they were nor did our realtor estate agent. I wish I had found out what they were and the potential problems they could cause early on. My family suffers from various allergies and I have a very active Australian cattle dog. We want to remove them asap, especially since they are pretty old and in bad shape. Any advice on what to do about saw dust or anything else we should look out for? Unfortunately we have neighbors directly on all sides of our fences that this will affect too.

    1. Amanda,

      It is fairly well documented that Grevillea robusta contains a multitude of toxins in its leaves, wood, flowers, seeds, etc.. Your family and your pets should be ok as long as you stay away from prolonged contact. If you contract a tree service company to remove yours, make it a point to let them know that their workers should consider wearing protective clothing and masks/face shields, which they should plan to remove and have cleaned after they are done! Thanks for writing and stay safe!
      Victor Riquelme
      Big Olive’s LLC

  3. I am a wood carver, and made a few spoons out of this wood and developed a red, itchy rash covering my chest, arms and neck areas. Needless to say I will never use this wood again.

Leave a Reply

Your email address will not be published. Required fields are marked *

Click to listen highlighted text!