The Garden on the Roof

When Mateo's school in Lisbon announced that the roof would be turned into a garden, most students thought it was a joke. The roof was grey, hot and covered with old pipes. But their science teacher, Ms Costa, was serious. "A green roof keeps the building cooler in summer," she explained, "and it gives bees and butterflies a place to live." The class had to plan everything themselves. Mateo and his friends measured the space, looked up which plants can survive strong sun, and wrote a list of what they needed. They were not allowed to spend more than two hundred euros, so they asked local shops for help. A garden centre gave them soil, and a neighbour donated old wooden boxes. It took three Saturdays to finish the work. They planted herbs such as thyme and rosemary, as well as small flowers that attract insects. A simple system collects rainwater, which is used for watering. By the end of the summer, the roof looked completely different. Teachers noticed that the top floor was several degrees cooler than before. Even more surprising, butterflies appeared in July. "I never thought we could change a place like that," Mateo told the school newspaper. "Now I check the plants every morning before lessons."