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By Tim Clancy.

Glorious Grevillea Gem

One of my favorite trees these days is the silk oak, Grevillea robusta. I was fascinated by its flowers when I first saw it many years ago. It is an evergreen tree that can grow to be 60’ tall with a crown spread of 50’ at times. Along with Banksia, macadamia, and proteas it’s a member of the Proteaceae family.

The leaves are reminiscent of an oak. As are many of the trees and plants we use in San Diego it is native to Australia. Able to readily adapt, the tree has naturalized in many locations around the world. "Naturalized" in the botany world happens when a plant does not need human intervention to succeed outside of its native range. In Hawaii and Florida, while naturalized, the tree is also considered an invasive species.

In Encinitas, there is a park located in an HOA that has a grove of silk oaks. When these trees are in bloom it is a sight to behold. Bright orange blossoms cover the trees, and it is magnificent. I like to go check them out a couple times a year and enjoy them through the seasons.

A few weeks ago, I was in the neighborhood, so I decided to go check them out. Well guess what, someone had decided that these fine specimen trees needed some cosmetic work done. Now I am not sure what the objective was in “treating” these trees. Maybe whoever oversees them thought they deserved to be punished for some nefarious misdeed. Perhaps some well meaning “arborist” convinced the tree manager that pruning off perfectly fine functioning branches would improve tree health. (I am really getting tired of people who promote pruning to “improve” tree health). I suppose it's possible that someone decided that the tree needed a “haircut,” because the way the tree was naturally growing somehow offended that person. Whatever the reason was from a horticultural perspective it was unnecessary to prune these trees and only served to negatively affect tree health.

I realize that people often prune trees for purely aesthetic reasons. Other than specialized pruning such as pollards, espaliers, topiary pruning for aesthetics has always baffled me. We pretty much know how a tall and wide tree will grow and what form it will ultimately take. So why are people so intent on changing what a tree does? They grow branches and leaves for a reason and that reason is not so members of the TMG (Tree Mutilation Guild) can make boat payments! Of course, we need to prune trees for safety reasons. I certainly am not advocating that a tree be allowed to obscure a stop sign or the address of your house. We also need to provide adequate clearance over roadways and sidewalks. I am not unreasonable about the subject.

Pruning for aesthetics is fine if you own the tree. Community owned trees on the other hand should not be pruned for aesthetics because who is the decider? What some people may find aesthetically pleasing others may find very objectionable. I for one can’t see what’s attractive about the group of trees in the picture below. I have also included a photo of a flower which of course I think is fabulous.

These trees should be so full you see no trunk!

Tim Clancy & Associates LLC P.O. Box 1180 – Cardiff-by-the-Sea, CA 92007

International Society of Arboriculture Certified Arborist No. WE-0806A

International Society of Arboriculture - Tree Risk Assessment Qualified


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