Battalions of soldiers will be reinforced by thousands of teachers and students coming from 947 public elementary and high schools in Pampanga, Tarlac, Nueva Ecija, Aurora, Bataan, and Zambales in the tree planting.
The simultaneous tree planting kicks off at 8 a.m. at the Lubao Elementary School in Lubao, Pampanga, hometown of President Arroyo.
Army spokesman Maj. Ernesto Torres said todays activity is the Armys contribution to Berdeng Pilipinas, a project of the national government to re-green denuded forest areas.
"The simultaneous planting of more than 500,000 seedlings is a feat that may be considered for the Guinness Book of World Records," he said.