Scheduled for completion later this year, Bosco Verticale, by Boeri Studio, will be the world’s first vertical forest. The project’s inspired many supporters, but also many detractors. Speaking to its controversiality, Lloyd Alter, the architect, sustainable design enthusiast, and managing editor of Treehugger, called it “the rendering that launched a thousand blog posts.”

And perhaps no blogger caused more stir in the architecture community than Tim De Chant, who implored “can we please stop putting trees on skyscrapers”? De Chant’s article set off a maelstrom of comments from ArchDaily users, who vigorously debated both for and against the idea of putting trees on buildings.

To get to the bottom of this, we talked with Lloyd Alter himself about vertical forests and the real challenges and benefits they present. Lloyd is a regular contributor to Inhabitat, The Huffington Post and numerous other publications; he also teaches at Ryerson University School of Interior Design. Read on for Lloyd’s take on this controversial trend, after the break.