That tree, which was toppled during a 2002 storm, was considered the largest White oak in the country.
Grove, a member of Washington County's forestry board, brought four potted seedlings from her yard.
"You guys ready to plant some huge trees? We need lots of muscle," Emilie Cooper of Maryland Forest Service and Western Maryland Resource Conservation & Development joked about the small seedlings.
Cooper showed the five boys how to flip a pot while holding a seedling in place, then lower it into a hole and pack it in.
Jack Grunow and Bret Snodderly worked at one hole while Alex Wiles and Hunter planted at another. Evans assisted J.T. Mason at a third hole.
The boys go to Emma K. Doub School for Integrated Arts & Technology. They were spending time at the outdoor center this week.
Once the seedlings were in the ground, Cooper showed the boys how to place tubes around them, to protect the seedlings as they grow.
Soon, the lunch bell sounded and the boys ran to eat.
About 60 school children were at Hagerstown's Fairgrounds Park on Wednesday for an Arbor Day event there, according to Susie Salvagni, an events/program specialist for the city.
She said Eastern Elementary School's show choir performed. Members of South Hagerstown High School's Key Club read aloud the history of Arbor Day.
Pangborn, Potomac Heights and Salem Avenue elementary school students also attended.
Salvagni said Maryland Forest Service presented the city with a Tree City USA award for the 21st year in a row.
According to the Forest Service's Web site, a Tree City must have a tree board or department responsible for tree care, an urban forestry program supported by the spending of at least $2 per capita and a proclamation recognizing and celebrating Arbor Day.