PHILADELPHIA (CBS) — Volunteers from across America, working for PHS and the national non-profit Alliance for Community Trees, planted over 20 trees in Old City Sunday afternoon.

Participants who were in town for the annual meeting of ACT, spread out across the Old City neighborhood planting 24 trees in an effort to “TreeVitalize” the city.

ACT, the Alliance for Community Trees, will plant 1,000 trees in Philadelphia during the month of November as part of the initiative.

PHS and ACT, foundations dedicated to “improving the health and livability of cities by planting and caring for trees,” plan on organizing a three-state campaign to plant trees in 2011.

To learn more about how you can get involved with PHS or ACT, please visit ActTrees.org