Every year on the last Friday in April Americans observe National Arbor Day. Tree plantings and other events are held all across the United States to focus attention on the importance of trees in our communities and on our planet. Sponsored by the National Arbor Day Foundation, a non-profit group founded in 1872, Arbor Day somewhat overshadows another of the Foundation's national projects. It is called the "Tree City USA" program, and it recognizes communities that preserve, protect, and defend their trees every day of the year. VOA's George Dwyer recently visited a "tree city" just outside Washington.