Rooftop garden might seem like a development of modernity, but they actually date back to antiquity. Roof gardens have not only served to delight people, but also to grow food, provide flood control and insulate homes. Many cities across the globe are promoting the installation of rooftop gardens for these very reasons.
Rooftop gardens are most commonly found in cities where free ground level space is limited, heat build-up is of concern and water overflow is an issue. Gardens can actually reduce the overall heat absorption of a building, thus reducing energy consumption and helping fight smog. But that’s not the only thing these little environmental superheroes do. They also provide space for growing affordable and sustainable crops, recreation and migratory way stations for animals.
Just as ancient rooftop garden were instrumental in human survival, modern roof gardening might make a difference in our own future. Roof garden advocates believe that roof farming can be the answer to food insecurity in cities and environmentalists believe that these green spaces will have a positive impact on climate change mitigation and adaptations.
Rooftop garden, also called living roofs or green roofs, have many advantages, including providing more space for agriculture, adding beauty to the cityscape and increasing air quality. During photosynthesis, plants remove carbon dioxide from the air and release oxygen that we need to breathe.
On hot summer days, rooftop gardens may also keep buildings cooler than traditional roofs—especially larger buildings that often have tar and gravel roof surfaces. Because they sit in the direct sunlight for many hours, the temperature of traditional rooftops tends to rise above the actual air temperature. That heat radiates back into the environment, making urban areas much warmer than rural and suburban ones. If you live in a big city or have visited a shopping center with a lot of concrete and buildings during warm months, you might have noticed the temperature difference. When heat is radiated back into the environment from rooftops, an area with many buildings, like a city, can experience an increase in local air temperatures by as much as 5 to 7 degrees Fahrenheit! This phenomenon is called the urban heat island effect.
Rooftop garden take the enjoyment of plants to a new level. Cars rush by on the streets below while gardeners on rooftops and terraces enjoy the unusual perspectives offered by the setting. These gardens have a mood all their own. Because they are much smaller than the average back yard, they challenge gardeners to think about what is really essential, and the results can be unexpected and extremely striking.
Plants in rooftop gardens are exposed to more extreme conditions than plants in the ground, but many great garden plants will thrive if you choose carefully and take care of them. A watering can or a hose may be all you need, but consider installing drip irrigation, especially for large rooftop gardens.
Benefits of building a rooftop garden:
- Reduce stormwater runoff
- Reduce your air-conditioning costs
- Create habitat for birds, butterflies and bees
- Provide outdoor space for you to enjoy
- Beautify the built environment
- Improve air quality
- Allow you to grow food
- Earn LEED credits
