S6E9: Trees on Top — How Stress Tests, Substrate & Sensors Green “Impossible” Places with Daan Grasveld of The Urban Jungle Project

On a rooftop disguised as a public square outside Amsterdam’s public library, Nadina sits down with Daan Grasveld, co-founder of Urban Jungle Project, to explore how trees can thrive in the most unlikely urban places. What looks like a normal city square is actually the top of a parking garage—once barren, hot, and lifeless. Today, thanks to modular “jungle blocks,” it’s a cool, shaded micro-jungle alive with bees, birds, and people.Daan breaks down his “three S’s” — stress tests, substrate, and sensors — and explains how Urban Jungle Project lifts fully grown trees onto roofs, squares, balconies, and other “impossible” sites where traditional planting can’t go. We talk about green-as-a-service and why maintaining living systems is as important as installing them, the role of citizen science through QR-coded monitoring, and why the long-term goal is actually less technology through passive, resilient systems that let nature do the work.Together, we explore how modular forests cool cities, create instant biodiversity, and turn overlooked spaces into places people want to be. If you’ve ever looked at a roof, garage, or forgotten corner and wondered what it could become, this episode opens a new window into the future of urban nature.