Arbor Day Planting is an annual event celebrated in many countries around the world. It is a day dedicated to planting trees and saplings to help promote environmental conservation and sustainability. The term Arbor Day Planting can be broken down into two words: tree (4 letters) and SAPLING (7 letters). Tree is a woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground. SAPLING is a young tree, especially one that has been recently planted.