Mayor John Dennis was also in attendance to read a proclamation in honor of the holiday.
The holiday recognizes the importance of trees in communities.
Lilly Nature Center Director Dan Dunten also invited a group of individuals from Brookshire Learning Center.
Twenty Pre-K children helped plant trees along Lindberg Road.
Dunten said these young people are helping make the world better for their future.
"It's good to have little ones involved," said Dunten. "Because they get to see the fruits of their labor as they plant trees and watch as they grow."