Julius Morton Sterling was editor of the Nebraska City News and he was responsible for the first Arbor Day in 1872, when a million trees were planted. He understood that the prairies needed trees to hold moisture and to serve as windbreaks.
He wrote, "other holidays repose upon the past, Arbor Day proposes for the future." Tree planting was also emphasized when the first Earth Day was celebrated on April 22nd, 1970.
Those of us who have trees already established in our gardens enjoy their many benefits, including the hospitable environment they provide for wild flowers in the spring. Virginia bluebells "Mertensia virginica" grow well under deciduous trees, because they bloom before the trees leaf out.
Since they go dormant after they bloom, woodland settings give them the light they need to bloom and shade while they are resting. If they are given the right conditions, (fertile, moist, and neutral to slightly acid soil) they will happily self sow and form large colonies.
"Heaven on earth"
Gather the seed pods when they are brown and seal them in an envelope. Then sow them in the fall ½" deep. The plants resent being disturbed, so division doesn't work as well. Plants are available at garden centers. These natives have pink buds that open into flowers of the purest sky blue. When they bloom they create a patch of heaven on earth.