On October 21st, 2012, Bishop Norbert Trelle planted an “October Glory” red maple tree on behalf of the Catholic Diocese of Hildesheim, Germany.
On March 8th, 2014, during an ecumenical ceremony with members and guests of the Bishop’s Conference of the United Evangelical Lutheran Church in Germany (VELKD), Bishop Gerhard Ulrich, Presiding Bishop of the VELKD (left), and Bishop Norbert Trelle of Hildesheim (right) planted a pin oak tree as partner tree for the Diocese of Hildesheim.