Adding trees to the neighborhood has multiple benefits. Trees help filter urban pollution, they provide much coveted shade for those hot sun downer days of summer, they provide vertical visual interest, they provide protection from the wind. Plus, humans just tend to enjoy having trees around. Maybe it's the psychological pleasure derived from the texture and color, or perhaps for people in the desert, it's the oasis feeling they promote. The notion of 'sacred groves' is ancient and there are even studies that show how trees help us heal both emotional and physical wounds. Certainly it's a fact that people love trees. Certain trees, like the mighty Sequoias and the coastal Redwoods take on so much meaning that people even put their lives on the line to save them.
To memorialize the planting of trees can help create memories that unite people and place for a life time and even for generations. The ritual brings to life the otherwise metaphorical notion of putting down roots. They become, literally, the trees of life, the trees of our lives. We often hear statements like "My grandmother planted that tree" or "My father and I planted that tree." In this way, trees become part of the family.
An advantage to planting trees in one's own yard rather than in a public place is that you can tend to and protect the tree more easily. It isn't a selfish act, since the tree will be well cared for and as it grows your neighbors will begin to reap the visual and environmental benefits as well. Of course, if you love your neighbors, this is a good day to invite them over to help plant the tree, or at least to mix the cocktails while the gardeners plant the trees.
One of the tricks to planting trees for Earth Day -- whether deciduous trees like maples, fruit trees or conifers -- is to make sure the trees you plant are weather hardy for our harsh high desert climates. Find a place in your yard where the tree can grow without competition. Happy Earth Day!