Since its completion in 2014, Bosco Verticale (Vertical Forest)—a pair of residential towers in Milan, Italy, covered by vegetation—has become a striking symbol of environmental sustainability in architecture. Stefano Boeri intended his design, which features balconies that are home to hundreds of trees, to serve as a model for promoting urban biodiversity. However, the concept has faced skepticism: critics note that although the trees used in Bosco Verticale were specifically cultivated for the project, it’s too early to tell if they can thrive in this unusual setting.