Founded by John Rosenow in 1972 — the centennial of the first Arbor Day observance — the Arbor Day Foundation is the largest 501(c)3 nonprofit membership organization dedicated to planting trees. More than 1 million members, supporters, and valued partners have helped us plant more than 350 million trees in neighborhoods, communities, cities, and forests throughout the world to ensure a greener and healthier future for everyone.