Green ribbons, including this one on a tree on the dividing strip between northbound and southbound lanes of U.S. 421, have been tied around 250 trees in the downtown area to identify those that have been planted by the Madison Tree Board in the past five years. The trees were marked in celebration of Arbor Day, which fell at the end of April. The Arbor Day Foundation once again honored Madison with a Tree City USA designation in 2012, a distinction earned by the city every year since 2007. The Madison Tree Board will host an Arbor Day Celebration on Saturday at the Farmers Market at the Broadway Fountain with a free tree giveaway at 9 a.m. and a reading of a proclamation at 10 a.m. A plant exchange will be at 10 a.m. Saturday in the Jefferson County Public Library Hanover branch parking lot. Plants can be set up prior to 10 a.m. (Staff photo by Ken Ritchie/