On an overcast Seattle morning a woman named Kit Harrington and several preschool-age children are crouched around the edges of an upturned cedar log, looking intently at the moldering leaves, dirt, and bugs they have just exposed to the world.

“I see a cricket,” Harrington – who is one of the co-founders of Fiddleheads Forest School and previously a Montessori teacher – says to the group. The children tighten in around the log.

“Can I have a cricket?” a boy named Reese gasps. “I want one!” There is a temporary upset when a little girl named Lilly traps a cricket in her clear plastic bug jar before Reese finds one.

Each fall, a new crop of preschoolers sets out for their first taste of formal education. Usually, this means kids in classrooms, playing with blocks, painting, and training their bodies to sit still for what will be the next 13 years in a classroom. But right now a new experiment in early education is playing out in parks around Seattle, Washington. At Fiddleheads Forest School, three and four-year-olds will spend their whole school day outside – playing in the mud, climbing over logs, and learning about bugs and birds. Even in famously rainy Seattle, there are no buildings for this school. If there’s a storm, they take cover in a greenhouse.

The Fiddleheads “classroom” is a clearing under a canopy of cedar, fir, and maple trees in Washington Park Arboretum. Sprinkled around the clearing are different “stations” – a circle of logs to sit and eat lunch on, several more upturned cedar logs that are being used as tables for painting or for reading. The “Science,” station has laminated cards diagraming the life cycle of a preying mantis, a microscope, and a plastic terrarium to entomb the students’ captured crickets.

“Over there, that’s for shows,” a little boy named Bergan says, pointing to the theater – a rope strung between two trees with burlap cloth hanging down and parted in the middle for stage curtains. For many of the 14 students, this is their first week at Fiddleheads. They shriek and speed around the classroom wearing neoprene galoshes with dinosaurs and spiders on them and brightly colored Gore-Tex onesie rain-suits.

Forest preschools have been growing in popularity in the Pacific Northwest. In 2016, a forest school called Tiny Trees will begin classes in six city parks around Seattle. This year, the Orcas Island Forest School had its inaugural class in the San Juan Islands and last year, the Roslyn Outdoor School opened in a small town in the Cascade Mountains, about an hour-and-a-half from Seattle. Fiddleheads was started in 2012 by Harrington and Co-Director Sarah Heller under the umbrella of the nearby University of Washington, and it also expanded this year, more than doubling their class size to keep up with demand.

Forest schools originated in Europe – in Germany and parts of Scandinavia – but their explosive growth in Seattle right now can be seen, in large part as a response to the growing body of research linking preschool to critical child development and long-term success. This coupled with the lack of available – and affordable – seats in Seattle preschools has families clamoring to get in.

A 2014 report from the Bill and Melinda Gates Foundation said that “longterm studies showed participants having significantly improved life outcomes – from lower rates of incarceration to higher earnings and life satisfaction,” when they participated in “high-quality early learning.” The report was based in part on a 2013 study in Boston that showed significant improvements in children’s math and vocabulary skills as a result of attending preschool. The Boston program also was noted for having “narrowed, and in some cases completely eliminated, school-readiness gaps between minority and white children.” In essence, it found that all children benefited, but disadvantaged children benefited most. In his 2013 State of the Union address, President Obama called for high-quality preschool for every child in America: “We know this works,” he said.

Seattle has approximately 12,000 three- and four-year olds but over 25% of them are not enrolled in a preschool nor participating in any childcare programs. These realizations prompted Seattle voters and the city to pass a 2014 proposition funding a voluntary universal preschool program. This is the first year of implementation, but there still aren’t enough schools. It will take several years for the city to either build more or contract with existing programs.

With young Seattle families struggling to pay for preschool tuition and the city’s skyrocketing cost of housing, some education entrepreneurs see forest schools as an elegant way to reduce tuition and increase access to schools. Teachers can be paid more; all you have to do is get rid of the building.

It’s mid-morning and Harrington is working with a little boy named Kenny. They are holding a translucent green spray bottle and a small terry cloth towel. Together they gently spray the broad leaves of a dove tree with water, one by one washing and drying them with the towel.

“These are the veins,” Harrington says, holding a leaf.

“It’s so pretty,” Kenny says, examining them up close.

According to Harrington, outdoor settings serve as a rich learning environment for kids where they can learn control and how to complete a project with multiple steps, in this case, without just ripping the leaves apart. “There’s all these little lessons,” she says.

A little over a year ago Andrew Jay noticed his friends in Seattle were struggling to pay for their kids’ preschool and daycare. So, the longtime outdoor educator started investigating preschool models. Jay has spent time working for the YMCA, Outward Bound, and the National Outdoor Leadership School (NOLS). When he discovered Fiddleheads, he sensed an opportunity.

Rather than raise money to create new schools for Seattle’s universal preschool program, he reasoned, one could open preschools in the city’s numerous parks with significant savings (no facility costs). “There’s all this green space that is not being used from 9:00 am – 3:00 pm on a weekday that we could transition into outdoor classrooms and then at the end of the school day it goes back to being a city park for the general public,” Jay said.

In a little over a year, the public response has been overwhelming. So far, 802 families have enrolled their kids at Jay’s program, Tiny Trees, which opens in six parks around Seattle next fall. Families are already enrolling their kids now for 2018.

Jay’s hope is that these programs will reach what he calls “the forgotten middle” – families that make too much money for financial support, but still can’t afford preschool on their own.

The Tiny Trees curriculum is being designed according to the City of Seattle’s “high-quality” preschool requirements, which emphasize language, literacy, and math. However, both he and Harrington agreed that creating a quality experience in the outdoors depends on great teachers, more than standardized learning; teachers who can translate the uncertainties of a day in the woods – discovering a family of owls, making a fort out of branches – into rich educational opportunities.

Back in the Fiddleheads classroom several kids straddle a small tree stump that’s laying sideways on the ground.

“It’s a three-person motorcycle!” yells a little girl named Stella. They are crammed, front to back on the stump, the child in front using the tangle of roots as a steering wheel. As they rock back and forth on the mock-vehicle, a piece of wood gives way with a loud crack.

“We lost our engine!” one of them yells.

“Hit the brakes!” another child responds.

Looking on from several yards away, Harrington describes what she sees happening in this seemingly simple game. “There’s so much going on cognitively. Right now they’re learning what the rules of the game are, what their boundaries are, the interests of each other.”

Critics of forest schools accuse them of packaging the type of outdoor playtime that all kids once had, before things like “screen time” became a concern, a quaint idealization of urban parents. But advocates disagree.

Harrington says that what sets forest schools apart from conventional classrooms are the experiences that teach kids “self-regulation” or what she describes as “your system that allows you to reset when you encounter a problem… If you have a high IQ but you can’t negotiate problems, you won’t be successful in life.” The constantly changing environment of the outdoors is especially suited for these learning opportunities.

Forest school parents run the gamut in terms of backgrounds and interests. Judy Lackey is a Fiddleheads parent. Her son Milo is her second child to be enrolled in the school. Lackey is an attorney-turned-full-time mom of three and her husband works at Amazon. Part of the reason they chose forest school for their kids was to limit their exposure to technology that is increasingly being marketed to young children.“You hear the stats about how much screen time kids get and how little outside time,” she said. “I haven’t seen any studies about negative aspects of time for your kids being outside.”

Jay describes many of his parents as “Trader Joe’s-types” – middle-class families who are interested in reduced-cost preschool. For many of the parents at Fiddleheads, cost wasn’t a factor, but the specific curriculum and time spent outdoors was. Anne Singh, whose daughter Meera is at Fiddleheads, is an elementary school teacher and her husband is a microbiologist at the University of Washington. She says parents who enroll their children in forest schools are brought together by their desire for less screen time for their kids.

“I would much, much rather see my daughter playing with pinecones and sticks and dirt than see her interacting with a screen,” Singh said.

Lackey says her son Milo likes routines and that forest school challenged him in this way. “I think it was helpful to be somewhere where he didn’t know what was going to happen,” she said. “I think it helped him be more resilient and more flexible.”

Harrington attributes the recent interest in Fiddleheads as a response to how technology is isolating kids from the outdoors. “People are starting to see how disconnected we have become.” There is a growing body of knowledge about the importance of nature for children’s emotional and physical development.

Harrington notes that parents with preschoolers right now represent a bridge generation, one that knew a pre-internet and computer era, as well as our current technology-filled lives.

By 12:30, the Fiddleheads’ school day is coming to an end. Students tear around the classroom in a post-lunch, blood sugar rush. Suddenly a coyote howl plays out through the woods. “A-woo! A-woo!” It’s one of the teachers calling everyone to the circle, where they gather to sing a song before going home. Parents start appearing around the edges of the classroom, gingerly peeking through the overhanging branches, excited to see what their children have discovered.

This article originally appeared on Medium and is republished here with permission.