In November, the trust awarded the school $900 to spend on greenery native to the area and $100 to build bird houses.
"Why are we planting trees?" Evans asked the first period class. "For two reasons - erosion control and habitat growth."
Before leaving the building, he gave one last directive, "Everyone is to pick up a shovel." On their way out, they also picked up meter sticks and bottles filled with water.
Then, 24 pairs of sneakers marched down the hill toward Grove Run stream, near the football field.
Horticulturist Greg Ott, vice president of Ott's Horticulture Center in Chewsville, brought the foliage and demonstrated shoveling techniques. The finished hole should be square, not pointed like the end of a pencil, he said.
Ott's daughter, Carie, 11, helped him unload the plants from his truck at the stream. She is also in Evans' class.
In groups of four or five, students found white place markers and started shoveling. They positioned shrubs such as red barberry and honeysuckle in a 200-yard area along the stream.
Evans, 41, said storm water from the growing town has caused a lot of soil erosion at the stream.
"The shrub roots will act as little fingers, holding the dirt back," he told the class. "The plants' berries and flowers will attract insects and birds."
Water from the Grove Run stream eventually flows into the Chesapeake Bay.
Danielle Everett, 11, of Hagerstown, said science class is always exciting. "We're trying to help the Chesapeake Bay and stop pollution of the Bay."
"I dug the hole and put the tree down," said Brent Webb, 12, of Fort Ritchie.
"The Bay is really polluted," said Dustin Sier, 12, of Smithsburg. "If we clean up where we are, it will really help a lot."
"Science isn't just science ... it's community," Evans said. "If we take care of our own backyard, it will make a difference down the line."
About 150 sixth-grade students in Evans' classes participated. Evans said they will measure and water the plants weekly - and create a map of the area.