The Once Upon a Time star joined singer Lance Bass, Entourage actress Constance Zimmer and reality TV star Francesca Eastwood by weeding and beautifying the green plots at Carson High School.
The famous faces later dined on food grown in the school's edible garden at the Environmental Media Association's (EMA) 3rd Annual School Garden Luncheon event.
Smart tells The Hollywood Reporter, "It's just so great to see this place come together. It's amazing to see it in full bloom."
Goodwin also posted a photo of the site on her Twitter.com page, writing, "My lunch was grown by the students of Carson Senior High School! EMA knows delicious."