Guest Post by David Taylor, Johns Hopkins University The Arbor Day Foundation’s ambitious tree-planting initiative to plant 100 million trees has deep roots, so to speak. They include a World War II campaign to plant trees across America. Every Arbor Day from 1942 through 1946, a patriotic tree-planting drive brought thousands of children, adults and politicians together to increase the country’s tree cover. Mostly, they were planting cork oak seedlings. There was a reason for that. Tree Products in American Life The planting campaign was the brainchild of the head of a Baltimore-based bottle-cap company named Crown Cork and Seal. A fact of life from then rarely remembered today: thin slivers of cork were used in bottle caps to make the seal tight and keep the pop in carbonated sodas.   In fact, before we had cheap plastic, thin sheets of cork (the bark from the cork oak) were used in all kinds of seals and insulation. America imported nearly half the world’s cork output every year for these uses.  All that cork came from Mediterranean forests in Europe and North Africa. In 1939, those imports were threatened when Nazi Germany imposed a blockade of Atlantic shipping. Hitler ordered U-Boat submarines … Continue reading When Planting Trees Expresses Love of Country