From vertical gardens to green roofs, there is immense potential in all of the nooks and crannies of city spaces to provide food for its residents. Cities have long been held as bustling forums of new ideas in art, science, and culture. They hold the same promise of creative innovation in sustainability as well.
Have you ever considered the functional potential of a wall? It can actually serve as a great spot for growing food. Vertical gardens can be as simple as a tall, narrow shelf of planters, sitting by a sunny window indoors, or decorating an outdoor garden. The planters can be affixed directly to the wall, and can be made of wood, metal, or even burlap bags. You can have plants growing directly from a wall made of soil, as in the popular French museum near the Eiffel Tower, le Musee du quai Branly. This living wall, as its known, is about 200 meters long and 12 meters tall. In recent years, concepts for skyscraper farms (or sky farms) have emerged from all over the world. One proposed $200 million sky farm in Las Vegas would boast 30 floors of indoor farmland, producing enough food to feed 72,000 people per year. An awesome feature of sky farms is that they can produce as much as a 420 hectare farm, but will take up 3% of the true land space.
Rooftops are another oft-overlooked space in cities, ripe with possibility not only for growing food but also to reduce energy use and enhance stormwater management. They are especially noteworthy because they can help reduce what’s known as the urban heat island effect. This heat island effect means that in a metropolitan area, the temperature is significantly warmer than in surrounding rural areas. It’s caused by human activities, particularly construction materials that effectively retain heat. Green roofs help offset the urban heat island effect by removing heat from the air through evapotranspiration. Evapotranspiration is the process by which plants absorb water through their roots and release it through their leaves, where the water converts to air. On a hot summer day, the surface of a conventional rooftop can be up to 90ºF warmer.
Green roofs can be installed just about anywhere, so long as the roof’s weight-bearing ability is considered in the design. Green roofs absorb heat and act as insulators for buildings, reducing the energy needed for cooling and heating. They reduce air pollution and greenhouse gas emissions, improve indoor comfort and air quality, enhance stormwater management and water quality, and also provide wildlife habitat. Plants and soil naturally filter water and pollutants from rainfall.
So the next time you walk down your street, think about how those blank walls and roofs could be utilized to grow food. Perhaps when we fully utilize these spaces, we can truly feed ourselves with local food.