This article was originally published in EdSource.
At Parkway Elementary School in Sacramento, students climb on logs beneath 58 new trees, explore flowering plants and use outdoor spaces as an extension of their regular classrooms.
But it didn’t always look that way: the majority of the schoolyard used to be covered in blacktop.
A collaboration with Green Schoolyards America in 2024 helped transform a 15,000-square-foot area of the campus, giving life to 58 trees — from Valley Oaks to flowering Western Redbuds — and 44 shrubs. The project also included an arborist to care for the trees and resources to help teachers incorporate the new natural spaces into their lessons.
That transformation is one of many efforts taking shape across the state to make school campuses cooler and greener as temperatures rise. But an EdSource analysis found that 45% of California’s K-12 students attend schools where 5% or less of the area where students spend time is covered by tree canopy.
Schools and green-schoolyard advocates say adding trees and natural spaces can do more than provide shade: it can create places for students to play, learn and socialize, and may improve behavior and mental health.
At Washington Elementary in Berkeley Unified, a decades-old balance between nature and synthetic surfaces has evolved into a playground nestled in a forest. At 122nd Street Elementary in Los Angeles, students planted wildflower seeds as part of a campus transformation.
And through CalFire’s Green Schoolyards Grant Program, Gov. Gavin Newsom announced transformations at 215 schools statewide.
“Shade is very important, and so that’s why we started it,” said Chamberlain Segrest, the sustainability manager of Sacramento City Unified. “But it turned into so much more.”
Efforts across California
It’s rare for California students to attend schools with abundant trees or greenery, an EdSource analysis found.
About 45% of California’s K-12 students — more than 2.6 million — attend schools where 5% or less of student zones are covered by tree canopy. The median, according to a report by Green Schoolyards America, is 6.4% coverage in student zones.
The lack of shade is even more apparent: 44% of public schools have 5% or less tree canopy in student zones, while 45% have 6% to 15%, and about 11% have more than 15%.

Where trees are planted matters, too. Less than half of school tree canopies are accessible to students, while roughly 55% of trees and greenery are located around school perimeters, entrances or parking lots.
“Adults like to plant trees for themselves in the places that are in the parking lot and the perimeter,” said Sharon Gamson Danks, the CEO and founder of Green Schoolyards America. “We know about half the trees in California are planted in places adults use in the parking lot and the perimeter, and the other half of the trees are planted where the kids are, and that doesn’t leave very many.”
The average tree canopy in student zones is around 6%, Danks said. And many schools across the state are aiming to make their campuses 30% shade or green space.
“Across all of California, we need more trees,” Danks said. “But we specifically need more trees where the need is the greatest, where the places the schools are in (are) the hottest environments and have the least capacity to change that themselves financially.”
A changing climate
The need for more shade and green space comes as temperatures continue to rise.
Summer temperatures in California have increased by roughly 3% since 1896, with more than half of that increase occurring since the 1970s, according to the Scripps Institution of Oceanography.
About 2,600 public schools, including charters — more than a quarter of the state’s campuses — were in areas rated at high heat risk on Aug. 10, the week when many students returned to school, according to an EdSource analysis of CalHeat scores. Nearly 60% are elementary schools, and Los Angeles, Fresno and San Bernardino counties have the largest percentage of schools in such areas.
As temperatures rise, districts have had to adapt during summer sessions by reducing students’ time outdoors and adjusting physical activities.
Now, experts are concerned that higher temperatures are extending into the fall when schools are fully in session. On Oct. 5, as a heat wave increased temperatures to nearly triple digits in parts of Los Angeles and the Bay Area, nearly half of California’s public schools — about 4,900 — were in areas the state had rated heat risk as high or severe, almost double the number on Aug. 10.
“The goal should always be to choose metabolically significant solutions, and that means metabolic work that a child’s body is doing to cool down,” said Kelly Turner, a professor of Urban Planning and Geography at UCLA.
Shade, air conditioning and swimming pools can all help, she said, as can shifting recess times and adding water breaks.
“There’s a lot of creativity out there that can be done in the short run, because changing the infrastructure and making these big climate changes is going to be challenging,” Turner said. “Given that, in California particularly, most schools already don’t have the funding they need to make basic safety upgrades. And so, this kind of stuff kind of gets kicked down the road.”
Better behavior, less bullying
Beyond keeping kids cool, adding trees and greenery to campuses can provide a wide range of benefits, including more opportunities for play, as well as improved schoolyard dynamics and student well-being.
“Children that have things to do tend to be happier and less in need of pestering other children to entertain themselves,” Danks said. “So, if you have a green schoolyard, there are many opportunities for kids to engage in positive activities. And so, you find them engaged in those things, and they aren’t as interested in bothering the other kids.”
In turn, she said, bullying goes down.
Lisa Smith, principal at LAUSD’s 122nd Street Elementary in West Compton, said the addition of trees and more options for outdoor play has helped reduce conflict. At some schools, antisocial interactions and bullying were found to have dropped 40% to 50%, according to a study published in the American Journal of Preventative Medicine.
“We have kids out there playing card games, just sitting down, talking with their friends, enjoying it during recess and lunchtime,” Smith said of the $340,000 project, which also included field testing. “And so, it actually alleviates a lot of behavioral issues, too, because kids now have things that they want to do.”
Green spaces can also give teachers new opportunities for outdoor learning, from lessons about the environment to activities focused on social and emotional learning.
At LAUSD’s Eagle Rock Elementary, students sit in a circle on tree stumps, passing a talking stick that gives each child an opportunity to share any worries they may be experiencing.
It can be anything from “something at home, or something in the big wide world,” the teacher tells them, before pointing out a conflict between a hawk and crow — a real-time ecology lesson.
Greenery and trees can also support students’ mental health and give them a greater sense of purpose when they have a role in caring for their school environment.
“As part of the project, we supplied tools for stewardship: watering cans and trowels and buckets for pulling weeds and gloves. And so teachers started taking advantage of that,” said Ayesha Ercelawn, the associate director of education at Green Schoolyards America, which was involved in the transformation of Parkway Elementary in Sacramento.
Social workers began noticing changes in students’ mental health, and teachers said the kids seemed calmer.
“Change started happening so fast,” Ercelawn said.
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