In an open pasture outside her science class, 13-year-old Keira Loftus fearlessly holds up a dirt-covered earthworm in her left hand.

“They make black gold,” Loftus says with pride.

The seventh grader, along with her classmates at Leewood K-8 Center in Kendall, keeps the worms in a box full of organic compost so that nature’s recyclers can do what they do best – make nutrient-rich fertilizer for the students’ nationally recognized produce garden.

Leewood is the only school from Florida in the running for the Samsung Solve for Tomorrow competition, a nationwide contest focused on highlighting projects involving science, technology, engineering and math. Chosen out of 1,600 applications, the South Miami-Dade County school is among 15 finalists collecting online votes to win a technology grant worth more than $100,000.

“We want to expand our garden and donate the fruits and vegetables we grow to local food banks,” said science teacher Angela Holbrook, who began the project with her seventh-grade class last August.

Holbrook said it all started when her students asked why people in South Florida aren’t allowed to eat the fish living in the fresh water lakes and canals.

“They found out that the water is high in chemicals like mercury,” she said.

But the students wanted more answers.

Research led the seventh graders to learn that agricultural areas in central Florida use large amounts of synthetic pesticides on their crops. The byproducts of the pesticide chemicals find their way into the water, which then flows south to places like Miami-Dade County.

In response, the class decided to grow their own food, however under different circumstances – using only natural methods.

Holbrook taught her students how to irrigate plants by collecting rainwater in barrels and keep pests under control by bringing in ladybugs.

Fenced in using colorful wooden frames, twelve rectangular soil beds house the vegetables and fruits of the class’s labor – tomatoes, strawberries, cabbages, broccoli and several other leafy greens.

“Everything we grow starts out as a seed,” said student Joshua Benson, who is 13 years old. “We have to make sure that we don’t let anything over-bloom.”

Candy Loftus, Keila’s mom, noticed that her daughter is becoming more environmentally conscious.

“She talks about it a lot more ever since she got involved with the garden,” Candy said.

Students’ eating habits are also being affected.

Everything grown in the garden is later harvested and cooked at the school, said Holbrook. Her class enjoys making crunchy vegetable chips using kale, a type of cabbage with green leaves.

Twelve-year-old Gabriella Santana took her gardening lessons a step further and started planting her own food at home.

“I’ve been learning that pesticides can really hurt food,” Santana said. “I grow herbs like basil that my mom uses to cook.”

Since its inception more than six months ago, students at various grades at the school are participating in the project, from kindergarteners harvesting veggies to older students calculating the soil’s pH balance.

But ultimately, Holbrook is satisfied as long as her own students learn to understand the role they play in the ecosystem.

“This is teaching them that you can grow food and still be good to the environment at the same time,” she said.