May 8, 2018 1:59 PM

Deep in the woods of Sagaponack, The Green School connects children with nature. The year-round preschool program is eco-focused, hands-on—and turning 10 this year.“We focus in what we call a hidden learning style, where children are having fun and they’re playing, but yet we are incorporating learning by nature, which is all around us,” said the school’s founder, Mari Linnman. “You can draw letters in the sandbox, or count the number of sticks on the ground, or you can open the door to the chicken coop and count the number of chickens running out. [Education] doesn’t have to be in a traditional classroom.”

The farm-friendly classroom started out of the growing demand at a summer camp that Ms. Linnman has run for more than 23 years, the Art Farm Hamptons, which has a sister camp in New York City. The day camp experience has swelled from a one-woman operation to more than 400 campers and 100 employees.

After the birth of her second son, Mattias, in 2008, Ms. Linnman launched The Green School, mirroring the education she received in her home country of Sweden. The Green School was then just a cozy classroom for 12 preschool children, including Mattias, positioned in four horse stalls in her barn.

“Children, when they leave here, are going to their school of choice,” Ms. Linnman said. “At that point, going into kindergarten, they are really looking to have the children read and write. They should know their letters and numbers.”

Mattias Linnman now goes to school in the Sag Harbor School District. And the school has grown without him. There are a total of 30 children in the school programs, not including after-school activities.

With 10 years in the rearview mirror, there are now afternoon classes for children between the ages of 2 and 4, a “Grown Up and Me” class for ages 18 to 24 months, weekend activities caring for farm animals, community-driven school programs, school-break programs, field trips and summer camp.

Classes have a rich farm experience, which Ms. Linnman said strengthens the immune system, improves eyesight, attention span, creativity and social skills, decreases hyperactivity and depression, and promotes brain development and fine motor skills. Preschoolers tend soil, plant crops, care for animals, gather eggs from the chickens and learn to cook organically.

“We are starting to teach holistic medicine using food and essential oils, and now equine coaching and therapy,” Ms. Linnman said. “We give families a compost bin where they take their learning home.”

Shelly Suh of Sagaponack said the school allowed her children to get their feet wet and hands dirty, and, most importantly, to learn from it. Her daughter, Cybelle, 8, is now in the third grade, and her son, Mason, 5, is going into kindergarten in September. They attend school in Sag Harbor.

“We looked at the Montessori schools, we looked at the Country Day School, we looked at The Green School. It’s exceptional,” Ms. Suh said. “I think kids need to be outdoors as much as possible. [Ms. Linnman] teaches them about recycling and caring for animals. My daughter loves the animals. My son is very physically active. It’s just a better fit for us.

“We all have our technology—I don’t keep it from them—but when they’re young, they need to run around outside with pigs and horses, and not learning about them while looking at a computer screen.”

Tuition is between $5,000 and $9,000 per year, depending on how many days the children attend. Built into every tuition is a fund that helps children in Chiang Mai, Thailand, purchase uniforms and get transportation to school. There’s also scholarship funds available for children on the South Fork.

“I want our community to pay it forward,” Ms. Linnman said.