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TREES, PLEASE: A Shady Business: Citizens Need to Speak Up

By Robin Rivet.

Do you avoid parking under a tree because you’re concerned that bird or insect feces might ruin your car wash? Although there are still people who think car paint is more valuable than breathing clean air, I’d guess many gardeners seek out the largest, lonely shade tree in public parking lots in order to avoid frying on hot, summer days. Did you ever wonder why there are so few large trees around?

nder why there are so few large trees around? Tree size is often a result of a combination of poorly conceived, but well-intentioned state contracting laws, commercial property managers who skirt the intent of regulations, inadequate government oversight, and overly zealous insurance underwriters – all typically lacking scientific knowledge. There is also a concern that landscape architects, who are usually tasked with advising and updating landscape codes, typically advocate on behalf of design, not biology. So why should this matter to you?

I’ll explain. An ironic example of California tree pruning law gone awry is that you do not need a D-49 specialty contractor’s license unless a tree is over fifteen feet tall. That seems reasonable, right? After all, homeowners don’t want the government meddling if they choose to provide a ladder and hand saw to their favorite gardener in order to trim a small peach tree. There are key liability reasons why everyone should hire licensed and certified arborists anyway, but what about those parking lot trees? Why are there so many diminutive, deformed, and utterly useless tress when it comes to providing the shade many of us search for?

The answer lies in foolish incentives for commercial lots to keep all shade trees under 15 feet. HOAs, shopping malls, medical centers, and others are guilty of hiring unlicensed “tree pruners,” but taxpayers forfeit cleaner air, cooled parking lots, and the cumulative effects of diminished carbon sequestration from savagely pruned foliage and limbs. In most cases, this also results in tree topping, which defies other regulations found in state public resources codes. In the City of San Diego, one municipal code’s goal is to achieve 50% shade in commercial parking areas, preferably with evergreen trees, while phasing out palms. Of course, like most city policies, the verbiage is extremely complicated and allows for all sorts of nuanced interpretation. Frankly, it’s seldom enforced, as there are few tree wardens watching. Your city may completely lack any ordinance. Horticulturists need to be aware of countywide efforts to combat climate change by increasing the number of large-scale urban trees wherever possible. This means citizens need to speak up and demand our county’s trees are allowed to grow up.

Member Robin Rivet is an ISA Certified Arborist, UC Master Gardener, and City of La Mesa Environmental Commissioner. She can be reached at

Additional public resources on this topic:

  1. A lawyer’s perspective from the Center for Urban Forest Research at the USFS: forestry/products/3/cufr_151.pdf

  2. The City of San Diego’s 2017 Urban Forestry Program Five Year Plan: forestry_program_five_year_plan.pdf

  3. Contractors State License Board’s warning of unlicensed tree trimmers: Releases/2016/November_8a.aspx

  4. California Government Code Section 53067. Tree pruning, legislative declaration; specifications: files/pubs/CGC53067-TreePruning.pdf

  5. Contractors State License Board’s distinction between gardeners and landscapers: cslb. GardenerOrLandscaperWhatsTheDifference.pdf

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