Thanks to the sewage that ends up in the Belgian river The Dijle, a lot of surprising vegetation can be seen on its shores in Leuven. Tomato plants, pumpkin plants, kiwi plants and even fig trees grow there.
“These plants can grow in mud and through the cracks in the walls. The urban climate, which is typically a couple of degrees warmer than its surrounding areas, helps these plants grow”, explains Thomas Gyselinck, practical assistant in Biology at the Catholic University of Leuven.
The seeds come from, among other things, human excrement, which is why these plants are called toilet plants.