Neighborhood group warns about impact of upzoning on City's vital tree canopy
In response to plans to upzone all of San Jose to high-density, multi-unit neighborhoods, the community group Families and Homes warns that the plan could lead to a dramatic loss in the city's tree canopy.
What is currently happening to our Tree Canopy in San José? It is decreasing.
A 2021 San José Transportation Department study found that there has been almost a 2% loss of its Urban Forest between 2012 to 2018 or 1728 acres of loss tree canopy.
Additionally there has been a 2 – 3+ % loss of tree canopy in Districts 1, 5, 9 and 10. This report also notes “...replacing lost canopy takes 30–40 years...The City will have to add approximately 40,000 35-foot canopy spread trees to recover 1% of lost canopy cover, making the preservation of [existing]canopy cover the most cost effective and efficient way to increase canopy cover.”
The report further notes that “Single-family and multifamily residential lots account for 62% of City [of San José’s] land use and 70% of all trees.” Maintaining this tree canopy is critical.
This was occurring before the implementation of SB9 in San José. And the loss of tree canopy will increase even further if the “Missing Middle” proposal is implemented.” (See: General Plan Four-Year Review Policy Framework (see Item 2 page 2; pages 11-12 for main "Missing Middle" discussion)).
And the decline continues, as documented in 2025-2026 Santa Clara County Civil Grand Jury Report tilted “A Canopy in Decline: Is San José serious about expanding its tree coverage?,” in spite of efforts of the City to address the issue.
Tree canopy improves mental health, improves air quality, provides shade (cooling the city)
University of Washington social scientist Kathleen Wolf, PhD, states: “Neighborhood greening reduces depression, may help kids reduce ADHD symptoms, reduces our stress response, encourages physical activity, reduces signs of mental distress, increases cognitive memory, improves air quality and, overall, promotes significantly higher well-being.” (The Struggle to Save Seattle’s Urban Trees in the Face of Development | Seattle Magazine)
Trees also reduce heat islands and lower temperatures in the City and in neighborhoods – sometimes as much as 8 degrees.
How will the Implementation of the Missing Middle Proposal would adversely impact San José’s Tree Canopy
“Researchers used historical imagery from Google Earth to look for changes in tree canopy on 80 randomly selected parcels in the city [of Seattle which had implied 4-plexs], and found that parcels in the downtown, industrial, single- and multi-family zones lost canopy when developed. Anyone looking around the city can see how that happens:
"A small single-family house on a big, treed lot comes down, and the lot is scraped bare, or nearly so. When four units sprout up, there’s scarce room for new trees, particularly ones that need space to grow big. The same can happen with larger developments.” (The Struggle to Save Seattle’s Urban Trees in the Face of Development | Seattle Magazine).
And the current San José General Plan Task Force recommendations include putting 16+ units on a lot depending on the size. (See page 6 of GP Task Force May 20 Meeting Presentation on Missing Middle.)
Read more here.
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