The couple kicked off the planting movement in May 2010 in Monona, Wisconsin -- Imhoff's hometown -- where they put a Northern Red Oak in Winnequah Park with the help of family and friends.
This spring, the tree showed its first signs of life when it began budding. How do they know which tree is theirs? Each one is marked using a GPS so it's easy to find in the future.
Photo: Plant a Wish