Trees have multiple meanings in different cultures such as strength, perseverance and nature, and many residents in Tucson are adding another personal interpretation.

As part of a program with Tucson Clean and Beautiful, they are purchasing trees for $225 to honor a friend or family member who has passed away or still alive.

The trees are being being planted at Pantano River Park on Tucson's east side in a growing program that began in the 1990s at Paseo de los Arboles (Pathway of the Trees) along the Santa Cruz River.

Placido Dos Santos has trees in both parks. They honor his parents.

"I'm very grateful to have an opportunity to come to a place where I can experience time with the memory of my mother and my father...and that's very cherished to me because I like the environment, this is a beautiful setting and my parents' remains are not here," Dos Santos says.

At Paseo de los Arboles, organizers planted 600 trees on the Santa Cruz River bank and there are hundreds of additional spaces at Pantano River Park.

Joan Lionetti is the executive director of Tucson Clean and Beautiful and she says the goal is to expand the program in different parts of our community, as part of a river park loop that will encircle the city.

She says a place to commemorate pets may also become available some day.

Watch Tucson Clean and Beautiful Director Joan Lionetti discuss the organization's work: